PRE-PUBLICA TION EDITION - Nelson Education

PRE-PUBLICATION EDITIONThis is DRAFT MATERIAL for evaluation purposes only.The final published edition will contain:• Chapter Self-Quizzes• Unit Reviews• Unit Self-Quizzes• Appendix A:Skills Handbook• Appendix B:What Is Science?• Selected Answers• Glossary with PronunciationGuide• Index• Final Art & Photographs(In the pre-publicationedition “FPO” and “T/K”means For Placement Only.)See Unit D: Climate Change on pages 310 to 453to preview all unit features.

Grade 10 Author TeamChristine Adam-CarrOttawa Catholic School BoardMartin GabberFormerly of Durham DistrictSchool BoardChristy HayhoeScience Writer and EditorDouglas Hayhoe, Ph.D.Department of Education,Tyndale University CollegeKatharine Hayhoe, B.Sc., M.S.,Professor, Department of Geosciences,Texas Tech UniversityMilan Sanader, B.Sc., B.Ed., M.EdDepartment Head of Science,Holy Name of Mary CatholicSecondary SchoolSenior Program ConsultantMaurice DiGiuseppe, Ph.D.University of Ontario Instituteof Technology (UOIT)Formerly of Toronto CatholicDistrict School BoardProgram ConsultantsDoug FraserDistrict School BoardOntario North EastMartin GabberFormerly of Durham DistrictSchool BoardDouglas Hayhoe, Ph.D.Department of Education,Tyndale University CollegeJeff Major, M.Ed.Thames Valley DistrictSchool Board

appendix ASkillsHandbook598 Skills HandbookNEL

Contents1. Safe Science1.A. Having a Safe Attitude..... 6001.B. Specific Safety Hazards.... 6011.C. Accidents Can Happen. ... 6021.D. Safety Conventions andSymbols .. . . . . . . . . . . . . . 6022. Scientific Tools andEquipment2.A. Working with DissectingEquipment.............. 6042.B. Testing for ElectricalConductivity. ........... 6042.C. Using the pH Meter.. . . . . . 6042.D. Using the Microscope .. . . . 6052.E. Using Other ScientificEquipment.............. 6083. Scientific Inquiry Skills3.A. Thinking as a Scientist .. . . 6103.B. Scientific Inquiry.. . . . . . . . 6104. Research Skills4.A. General ResearchSkills.................. 6184.B. Using the Internet .. . . . . . . 6194.C. Exploring an IssueCritically .. . . . . . . . . . . . . . 6205. Using Mathematics inScience5.A. SI Units............... 6245.B. Solving Numerical ProblemsUsing the GRASS Method. . 6265.C. Scientific Notation ........ 6265.D. Uncertainty in Measurement.. 6285.E. Using the Calculator....... 6315.F. Working with Angles...... 6336. Data Tables and Graphs6.A. Graphing Data......... 6346.B. Using Computers forGraphing.............. 6366.C. Interpreting Graphs...... 6367. Study Skills7.A. Working Together .. . . . . . 6377.B. Setting Goals and MonitoringProgress.. . . . . . . . . . . . . 6387.C. Good Study Habits...... 6408. Literacy8.A. Reading Strategies.. . . . . 6418.B. Graphic Organizers.. . . . . 6429. Latin and Greek Root Words10. Periodic TableNEL Contents 599

1Safe Science1.A. Having a Safe AttitudeScience investigations can be a lot of fun, but certainsafety hazards exist in any laboratory. You shouldknow about them and about the precautions youmust take to reduce the risk of an accident.Why is safety so important? Think about the safetymeasures you already take in your daily life. Yourschool laboratory, like your kitchen, need not bea dangerous place. In any situation, you can avoidaccidents when you understand how to use equipmentand materials and follow proper procedures.For example, you can take a hot pizza out of theoven safely if you take a few common-sense safetyprecautions. Similarly, corrosive acids can be usedsafely if appropriate safety precautions are taken.Safety in the laboratory combines common sensewith the foresight to consider the worst-case scenario.The activities and investigations in this textbook aresafe, as long as you follow proper safety precautions.General laboratory safety rules are outlined below(Table 1). Your teacher may provide you withadditional safety rules for specific tasks.Table 1 Practise Safe Science in the ClassroomBe science ready Follow instructions Act responsibly• Come prepared with your textbook,notebook, pencil, and anything elseyou need.• Tell your teacher about any allergies ormedical problems.• Keep yourself and your work area tidy andclean. Keep aisles clear.• Keep your clothing and hair out of the way.Roll up your sleeves, tuck in loose clothing,and tie back loose hair. Remove any loosejewellery.• Wear closed shoes (not sandals).• Do not wear contact lenses while doinginvestigations.• Read all written instructions carefullybefore you start an activity or investigation.• Do not enter a laboratory unless a teacheris present or you have permission to do so.• Listen to your teacher’s directions. Readwritten instructions. Follow them carefully.• Ask your teacher for directions if you arenot sure what to do.• Wear eye protection or other safetyequipment when instructed by your teacher.• Never change anything, or start an activityor investigation on your own, without yourteacher’s approval.• Get your teacher’s approval before you startan investigation that you have designedyourself.• Pay attention to your own safety andthe safety of others.• Know the location of MSDS (MaterialSafety Data Sheet) information, exits,and all safety equipment, such as thefirst-aid kit, fire blanket, fire extinguisher,and eyewash station.• Alert your teacher immediately if you see asafety hazard, such as broken glass, a spill,or unsafe behaviour.• Stand while handling equipment andmaterials.• Avoid sudden or rapid motion in thelaboratory, especially near chemicalsor sharp instruments.• Never eat, drink, or chew gum in thelaboratory.• Do not taste, touch, or smell any substancein the laboratory unless your teacher asksyou to do so.• Clean up and put away any equipment afteryou are finished.• Wash your hands with soap and water atthe end of each activity or investigation.600 Skills Handbook NEL

1.B. Specific Safety HazardsFollow these instructions to use materials andequipment safely in the science classroom.1.B.1. ChemicalsSome of the chemicals recommended for use in thiscourse are dangerous if used incorrectly. Be sure tofollow these rules to avoid accidents.• Assume that any unknown chemicals arehazardous.• Reduce exposure to chemicals to the absoluteminimum. Avoid direct skin contact, if possible.• When taking a chemical from a container, firstcheck the label to be sure you are taking thecorrect substance. Replace the lid securely whenyou have taken what you need.• Never use the contents of a container that hasno label or has an illegible label. Give any suchcontainers to your teacher.• Place test tubes in a rack before pouring liquidsinto them. If you must hold a test tube, tilt it awayfrom you, and others, before pouring in a liquid.• Pour liquid chemicals carefully (down the side ofthe receiving container or down a stirring rod)to avoid splashing. Always pour from the sideopposite the label so that drips will occur onlyon the side away from your hand.• When you are instructed to smell a chemical byyour teacher, first take a deep breath to fill yourlungs with just air, then waft or fan the vapourstoward your nose.• Do not return surplus chemicals to stock bottlesand do not pour them down the drain. Disposeof excess chemicals as directed by your teacher.• If any part of your body comes in contact witha chemical, wash the area immediately andthoroughly with cool water. Rinse affected eyesfor at least 15 minutes. Alert your teacher.1.B.2. Heat SourcesHeat sources, such as hot plates, light bulbs, andBunsen burners, can cause painful burns. Use cautionwhen there are hot objects around.• Secure your Bunsen burner to a retort stand witha clamp before lighting it.• Your teacher will show you the proper method oflighting and adjusting the Bunsen burner. Alwaysfollow this method.• Never leave a lighted burner unattended as aclean blue flame is almost invisible.• Never heat a flammable material over a Bunsenburner. Make sure there are no flammablematerials nearby.• Never look down the barrel of a burner.• When heating liquids in glass containers, useonly heat-resistant glassware. If a liquid is to beheated to boiling, use boiling chips to prevent“bumping.” Keep the open end of the containeraway from yourself and others. Never allow acontainer to boil dry.• When heating a test tube over a Bunsen burner,use a test-tube holder and a spurt cap. Hold thetest tube at an angle, with the opening facingaway from yourself and others. Heat the upperhalf of the liquid first and then move it gentlyinto the flame to distribute the heat evenly.• Always turn off the gas at the valve, not using thegas-adjustment screw of the Bunsen burner.• If you burn yourself, immediately apply coolwater to the affected area and inform yourteacher.1.B.3. Glass and Sharp ObjectsHandle glass carefully: it can break, leaving sharpedges and splinters.• Never use glassware that is broken, cracked,or chipped.• Never pick up broken glass with your fingers.Use gloves as well as a broom and a dustpanto remove glass from the area.• Dispose of glass fragments in special containersmarked “Broken Glass.”• If you cut yourself, inform your teacherimmediately. Embedded glass or continuedbleeding requires medical attention.• Select the appropriate instrument for the task.Never use a knife when scissors would work better.• Never carry a scalpel in the laboratory with anexposed blade; transport it in a dissection caseor box or on a dissection tray.NEL1. Safe Science 601

• Make sure your cutting instruments are sharp.Dull cutting instruments require more pressurethan sharp instruments and are, therefore, muchmore likely to slip. If your scalpel blade needs tobe changed, ask your teacher to change it for you.• Always cut away from yourself and others. Cutdownward, on a tray, cutting board, or papertowel.1.B.4. Electricity and Light• Never touch an electrical device, electrical cord,or outlet with wet hands.• Keep water away from electrical equipment.• Do not use the equipment if wires or plugs aredamaged or if the ground pin has been removed.• If using a light source, check that the wires ofthe light fixture are not frayed and that the bulbsocket is in good shape and is well secured toa stand.• Make sure that electrical cords are not a trippinghazard.• When unplugging equipment, hold the plug toremove it from the socket. Do not pull on the cord.• When using variable power supplies, start at lowvoltage and increase slowly.• Do not look directly at any bright source oflight. You cannot rely on the sensation of pain toprotect your eyes.• Never point a laser beam (directly or afterreflection) at anybody’s eyes.1.B.5. Living Things• Treat all living things with care and respect.Never treat an animal in a way that would causeit injury or harm.• Animals that live in the classroom should be keptin a clean, healthy environment.• Wear gloves and wash your hands before andafter feeding or handling an animal, touchingmaterials from the animal’s cage or tank, orhandling bacterial cultures.• Human blood, urine, or saliva samples shouldnot be tested or used in investigations due to therisk of contracting a disease from these fluids.1.C. Accidents Can HappenThe following guidelines apply if an injury occurs,such as a burn, a cut, a chemical spill, ingestion,inhalation, an electrical accident, or a splash inthe eyes.• If an injury occurs, inform your teacherimmediately.• If the injury is from contact with a chemical,wash the affected area with a continuous flowof cool water for at least 15 minutes. Removecontaminated clothing. Consult the MaterialSafety Data Sheet (MSDS) for the chemical; thissheet provides information about the first-aidrequirements. If the chemical is splashed intoyour eyes, have another student assist you ingetting to the eyewash station immediately. Rinsewith your eyes open for at least 15 minutes.• If you have ingested or inhaled a hazardoussubstance, inform your teacher immediately.Consult the MSDS for the first-aid requirementsfor the substance.• If the injury is from a burn, immediately immersethe affected area in cold water. This will reducethe temperature and prevent further tissuedamage.• In the event of electrical shock, do not touch theaffected person or the equipment the person wasusing. Break contact by switching off the sourceof electricity or by removing the plug.1.D. Safety Conventions andSymbolsThe activities and investigations in Nelson SciencePerspectives 10 are safe to perform providedprecautions are taken. This is why general safetyhazards are identified with caution symbols (Figure 1).Figure 1 Potential safety hazards are identified withcaution symbols.602 Skills Handbook NEL

More specific hazards, related to dangerouschemicals, are indicated with the appropriate WHMISsymbol. Make sure that you read the information andassociated instructions (in red type) carefully. Youmust understand and follow these instructions in orderto perform the activity or investigation safely. Checkwith your teacher if you are unsure.1.D.1. Workplace Hazardous MaterialsSafe Information ScienceSystem (WHMIS) SymbolsThe Workplace Hazardous Materials InformationWorkplace System (WHMIS) Hazardous provides Materials Information workers and System students (WHMIS) withcomplete and accurate information about hazardousproducts. Clear compressed and standardized labels dangerously must bepresent on gas the product’s original container reactive material or must beadded to other containers if the product is transferred.If the material flammableSafe Scienceis hazardous, and the label biohazardous will include onecombustibleor more of the WHMIS symbols (Figure infectious 2). materialWorkplace HazardousmaterialMaterials Information System (WHMIS)poisonous andinfectious materialoxidizing compressedcausing dangerously immediatematerial gasand reactive serious material toxiceffectsflammable andcombustiblecorrosive materialmaterialbiohazardouspoisonous andinfectious materialinfectious materialcausing otherpoisonous andtoxic effects1.D.2. Hazardous Household ProductSymbols (HHPS)The Canadian Hazardous Products Act requiresmanufacturers of consumer products to include asymbol that specifies both the nature and the degreeof any hazard. The Hazardous Household ProductsSymbols (HHPS) were designed to do this. Thesymbol is made up of a picture and a frame. Thepicture tells you the type of danger. The frame tellsyou whether it is the contents or the container thatposes the hazard (Figure 3).Hazardous Household Product Symbols (HHPS)SymbolDangerExplosiveThis container can explode if it isheated or punctured.Hazardous Household Corrosive Product Symbols (HHPS)This product will burn skin or eyes on contact,or throat and stomach if swallowed.Symbol DangerFlammableExplosiveThisThisproduct,containerorcanits fumes,explodewillif itcatchisfire easilyifheatedexposedor punctured.to heat, flames, or sparks.PoisonousCorrosiveLicking,This producteating,willdrinking,burn skinor sometimesor eyes on contact,smelling,thisor throatproductandisstomachlikely to causeif swallowed.illness or death.infectious materialoxidizingcausing immediatematerialand serious toxic Figure 3 Household Flammable Hazardous Products Symbols (HHPS)effectsappear on many This products product, that or are its used fumes, in will the home. catch fire A triangular easilyframe indicates if that exposed the container to heat, flames, is potentially or sparks. dangerous. AnPractise Safe Science in the Classroompoisonous andoctagonal frame indicates that the product inside the containercorrosiveinfectious material poses a hazard.PoisonousBe science ready.materialcausingFollowotherinstructions. Licking, Act eating, responsibly. drinking, or sometimes smelling,toxic effectsthis product is likely to cause illness or death. Figure2WHMIS symbols CSH-F01-SHOS10SB.aiidentify dangerous materialsthat are used in all workplaces, including schools. Practise Safe Science in the Classroom Be science ready. Follow instructions. Act responsibly. CSH-F01-SHOS10SB.ai NEL 1. Safe Science 603

2Scientific Tools and EquipmentSelecting the correct tools and equipment and usingthem properly are essential for your safety and thesafety of your classmates.2.A. Working with DissectingEquipmentDissection tools are very sharp and must be handledcarefully. Read through the following safety tipsbefore you begin any dissections (Figure 1).• Always hold the dissection tool by the handle.• To move dissection equipment to and from yourworkstation, place all tools in the dissection trayand carry the tray with both hands. Do not carrytools by hand. If you forgot a piece of equipment,carry the tray back to get what you need.• At your workstation, imagine your dissectiontray sitting in the middle of a 30 cm circle (aboutthe size of a large dinner plate). The tools neverleave this circle. If you leave your workstationor turn to answer a question, place the tools inthe dissection tray. Tools must always lie flat onthe inside or outside of the dissecting tray, notpropped up on the side of the tray.• Always cut away from yourself and others. Cutdownward onto a tray.• If you are asked to rinse a tool after you haveused it, remember that the tool is sharp. Hold itby the handle and rinse it under running water;do not wipe sharp edges or points.2.B. Testing for ElectricalConductivityBefore you start any conductivity testing, ask yourteacher for specific operating instructions on yourschool’s equipment (Figure 2). Devices used to testelectrical conductivity vary considerably. Two metalelectrodes are inserted into the sample to be tested.Figure 2 You should use only low-voltage (battery-powered)conductivity testers.In many cases, if the sample conducts electricity,the conductivity tester gives a positive result (e.g., alight bulb turns on). Some conductivity testers givevariable results (Table 1).Table 1 Results of Conductivity TestingObservationbright glowfaint glowno glowSamplegood conductorpoor conductornonconductor (insulator)2.C. Using the pH MeterpH meters are used to measure acidity or alkalinity(Figure 3). Your teacher will provide specific operatinginstructions for your school’s pH meters. Most pHmeters need to be calibrated by placing the probeinto a solution of a specific pH and then adjusting themeter so that it displays this pH value.Figure 1 Use safety equipment and always work within a30 cm circle at your workstation when dissecting.Figure 3 A pH meter604 Skills Handbook NEL

2.D. Using the MicroscopeTo view cells and other small objects closely, you willuse a microscope (Figure 4). You will most likely usea compound light microscope that uses more thanone lens and a light source to make an object appearlarger. The object is magnified first by the lens justabove the object: the objective lens. Then that imageis magnified by the eyepiece: the ocular lens. Thecomparison of the actual size of the object with thesize of its image is called the magnification. The partsof a compound light microscope and their functionsare listed in Table 2.revolvingnosepieceobjectivelensstageclipsdiaphragmocular lens(eyepiece)body tubecoarse-adjustmentknobfine-adjustmentknobarmlightsourcebaseTable 2 Parts of a Light MicroscopeFigure 4 A compound light microscopePartstageclipsdiaphragmobjective lensesrevolving nosepiecebody tubeeyepiece (ocular lens)coarse-adjustment knobfine-adjustment knoblight sourceFunction• supports the microscope slide• has a central opening that allows light to pass through the slide• holds the slide in position on the stage• controls the amount of light that reaches the object being viewed• magnify the object• have three possible magnifications: low power (4×), medium power (10×), and high power (40×)• holds the objective lenses• rotates, allowing the objective lenses to be changed• contains the eyepiece (ocular lens)• supports the objective lenses• is the part you look through to view the object• magnifies the image of the object, usually by 10ו moves the body tube up or down to get the object into focus• is used with the low-power objective lens only• moves the tube to get the object into sharp focus• is used with medium-power and high-power magnification• is used only after the object has been located, centred, and focused under lower power magnificationusing the coarse-adjustment knob• may be an electric light bulb or a mirror that can be angled to direct light through the object being viewedNEL2. Scientific Tools and Equipment 605

f2.D.1. Microscope SkillsThe basic microscope skills are presented asinstructions. This allows you to practise theseskills before you need to use them in the activitiesin Nelson Science Perspectives 10.Materials• scissors• microscope slide• cover slip• medicine dropper• compound microscope• compass or Petri dish• pencil• transparent ruler• small piece of newspaper with writing• small piece of onion membrane• water• two pieces of thread, different coloursPreparing a Dry MountA dry mount is a way to prepare a microscope slidethat does not use water.1. Find a small, flat object, such as a single letter cutfrom a newspaper article. A letter “e” works well.2. Place the object in the centre of a microscopeslide.3. Hold a cover slip between your thumb andforefinger. Place the edge of the cover slip toone side of the object (Figure 5). Gently lowerthe cover slip onto the slide so that it coversthe object.fPreparing a Wet MountA wet mount is a method of preparing a microscopeslide that uses a drop of water.1. Find a small, flat object such as a piece of onionmembrane.2. Place the object in the centre of a microscopeslide.3. Place one or two drops of water on the object(Figure 6).Figure 64. Holding the cover slip with your thumb andforefinger at a 45° angle, place one edge of thecover slip on the slide (Figure 7). Gently lowerthe cover slip, allowing the air to escape.Figure 7Viewing Objects Under the Microscope1. Make sure that the low-power objective lens ispositioned over the diaphragm. Either raise theobjective lens or lower the microscope stage asfar as possible. Place your dry-mount preparedslide in the centre of the stage. Use the stage clipsto hold the slide in position. Turn on the lightsource (Figure 8).ffFigure 5Figure 8606 Skills Handbook NEL

2. View the microscope stage from the side. Then,using the coarse-adjustment knob, lower the lowpowerobjective lens until it is close to the object.(Some microscopes have moveable stages, ratherthan moveable lenses.) Do not allow the lens totouch the cover slip (Figure 9). Make sure thatyou know which way to turn the knob to raise theobjective lens.Figure 93. Look through the eyepiece. Slowly raise theobjective lens using the coarse-adjustment knobuntil the image is in focus. Note that the object isfacing the “wrong” way and is upside down. Thearea you can see is called the field of view.4. Draw a circle in your notebook to represent thefield of view. Look through the microscope anddraw what you see. Make the object fill the sameproportion of area in your drawing as it does inthe microscope.5. While you look through the microscope, slowlymove the slide horizontally away from you. Notethat the object appears to move toward you. Nowmove the slide to the left. Notice that the objectappears to move to the right.6. Rotate the nosepiece to the medium-powerobjective lens. Use the fine-adjustment knob tobring the object into focus. Notice that the objectappears larger. Always use the fine adjustmentwhen the medium- or high-power objectives arein place; the coarse adjustment may damage theslide or lenses.7. Adjust the position of the object so that it isdirectly in the centre of the field of view. Rotatethe high-power objective lens into place. Again,use the fine-adjustment knob to focus the image.Notice that you see less of the object than you didunder medium-power magnification. Also noticethat the object appears larger.Determining the Field of ViewThe field of view is the area that you observe whenyou look through the microscope.1. Put the low-power objective lens in place. Placea transparent ruler on the stage. Position themillimetre marks of the ruler immediately belowthe objective lens.2. Use the coarse-adjustment knob to focus on themarks of the ruler.3. Move the ruler so that one of the millimetremarkings is just at the edge of the field ofview. Note the diameter of the field of view, inmillimetres, under the low-power objective lens(Figure 10).Figure 104. Rotate to the medium-power objective lens.Repeat steps 2 and 3 to measure the field of viewfor this lens.5. Most high-power objective lenses provide a fieldof view that is less than 1 mm in diameter, so itcannot be measured with a ruler.NEL2. Scientific Tools and Equipment 607

The following steps can be used to calculate thefield of view of a high-power lens.• Calculate the ratio of the magnification of thehigh-power objective lens to the magnificationof the low-power objective lens.ratio =• Use the ratio to determine the field of diameter(diameter of the field of view) under high-powermagnification.field of view diameter (high power) =field ____________________________of view diameter (low power)​ratioFor example, if the diameter of the low-powerfield of view is 2.5 mm, thenfield of view diameter (high power) = _______ 2.5 mm​10= 0.25 mmEstimating Size1. Measure the field of view, in millimetres, asshown above.2. Remove the ruler and replace it with the objectunder investigation.3. Estimate the number of times the object could fitacross the field of view.4. Calculate the width of the object:width of object =magnification of high-power lensmagnification of low-power lensFor example, if the low-power lens is 4×magnification and the high-power lens is 40×magnification, thenratio = 40 3 = 104 3Remember to include units.width of field of view________________________number of objects across field ​Putting Away the MicroscopeAfter you have completed an activity using amicroscope, follow these steps:1. Rotate the nosepiece to the low-power objectivelens.2. Raise the lenses (or lower the stage) as far aspossible.3. Remove the slide and the cover slip(if applicable).4. Clean the slide and the cover slip and returnthem to their appropriate location.5. Return the microscope, using two hands, to thestorage area.2.E. Using Other ScientificEquipmentFor some labs in this textbook, a specific list ofrequired materials and equipment is provided. Inothers, you have to decide what equipment andmaterials are necessary. Always keep safety in mindas you make your selections. Be sure to includeappropriate safety equipment, such as eye protection,gloves, or lab aprons, in your planning. For moreinformation on safety, refer to the Safe Science sectionof the Skills Handbook (page 600).608 Skills Handbook NEL

Figure 11 shows some of the equipment required forthe labs in this text.retort stand and ring clamp Erlenmeyer flask hot plate Petri dishelectronic balance wire gauze dropper bottle beaker tongstest-tubetest-tubeholderclamptriangular glass prismconverging lens lensBunsen burnerscoopula laboratory scoop calipers well plate ray boxplane mirror and mirror supportscalpelspark lighterforcepsFigure 11 Some typical laboratory equipmentNEL2. Scientific Tools and Equipment 609

3Scientific Inquiry Skills3.A. Thinking as a ScientistImagine that you are planning to buy a new personalelectronic device. First, you write a list of questions.Then you check print and Internet sources, visitstores, and talk to your friends to find out which isthe best purchase. When you try to solve problemsin this way, you are conducting an investigation andthinking like a scientist.• Scientists investigate the natural world todescribe it. For example, climatologists study thegrowth rings of trees to make inferences aboutwhat the climate was like in the past (Figure 1).• Scientists investigate the natural world to testtheir ideas about it. For example, biologists askcause-and-effect questions about the impact ofclimate change on water in the Arctic (Figure 3).They also propose hypotheses to answer theirquestions. Then they design investigations to testtheir hypotheses. This process leads scientists tocome up with new ideas to be tested and morequestions that need answers.Figure 3 Water samples can be tested for pH, dissolvedsubstances, and other impurities.Figure 1 Looking at and measuring tree rings tell scientistshow climate affects the growth of trees.• Scientists investigate objects to classify them. Forexample, chemists classify substances accordingto their properties (Figure 2).Figure 2 These compounds are similar because they areinsoluble in water.3.B. Scientific InquiryYou need to use a variety of skills when you doscientific inquiry and design or carry out anexperiment. Refer to this section when you havequestions about any of the following skills andprocesses:• questioning• hypothesizing• predicting• planning• controlling variables• performing• observing (Figure 4)• analyzing• evaluating• communicating610 Skills Handbook NEL

3. All the other conditions that remain unchangedand did not affect the outcome of theinvestigation are called the controlled variables.For example, consider the variables involved in aninvestigation to determine the effects of the mass ofdissolved salt on the boiling point of water (Figure 5).In this investigation,• the mass of dissolved salt is the independentvariable• the boiling point is the dependent variable• the amount of water in the beaker and the typeof salt used are two controlled variablesFigure 4 In each unit you will have an opportunity to develop newskills of scientific inquiry.3.B.1. QuestioningScientific investigations result from our curiosityabout the natural world. Our observations leadus to wonder “Why does that happen?” or “Whatwould happen if I …?” Before you can conduct aninvestigation, you must have a clear idea of what youwant to know. This will help you develop a questionthat will lead you to the information you want. Tryto avoid questions that lead simply to “yes” and “no”answers. Instead, develop questions that are testableand lead to an investigation.Sometimes, an investigation starts with a specialtype of question called a “cause-and-effect” question.A cause-and-effect question asks whether somethingis causing something else to happen. It might startin one of the following ways: What causes …? Howdoes … affect …?3.B.2. Controlling VariablesConsidering the variables involved is an importantstep in designing an effective investigation. Variablesare any factors that could affect the outcome of aninvestigation.There are three kinds of variables in aninvestigation:1. The variable that is changed is called theindependent variable, or cause variable.2. The variable that is affected by a change is calledthe dependent variable, or effect variable. Thisis the variable you measure to see how it wasaffected by the independent variable.NELFigure 5 Measuring the temperature at which water,containing a known mass of salt, boils.When scientists conduct controlled experiments(described in Section 1.1), they make sure that theychange only one independent variable at a time. Thisway, they may assume that their results are caused bythe variable they changed and not by any of the othervariables they identified.3. Scientific Inquiry Skills 611

3.B.3. Predicting and HypothesizingA prediction states what is likely to happen as theresult of a controlled experiment. Scientists basepredictions on their observations and knowledge.They look for patterns in the data they gather tohelp them understand what might happen nextor in a similar situation (Figure 6). A predictionmay be written as an “if … then …” statement. Forthis investigation, your prediction might be, “If theamount of dissolved salt is increased, then theboiling point will also increase.”Figure 6 A positively charged piece of plastic causes a streamof tap water to bend. What would you predict might happen if anegatively charged object is brought near the stream of water?In summary, a prediction states what you thinkwill happen. Remember, however, that predictionsare not guesses. They are suggestions based on priorknowledge and logical reasoning.A prediction can be used to generate a hypothesis.A hypothesis is a tentative answer about the outcomeof a controlled experiment along with an explanationfor the outcome. A hypothesis may be written inthe form of an “if … then … because …” statement.If the cause variable is changed in a particular way,then the effect variable will change in a particular way,and this change occurs because of certain reasons.For example, “If the amount of salt is increased, thenthe boiling point will also increase because salt formsattractions with water molecules and prevents themfrom changing into gas.” If your observations confirmyour prediction, then they support your hypothesis.You can create more than one hypothesis from thesame question or prediction. Another student mighttest the hypothesis, “If the amount of salt is increased,then the boiling point will not change because theattractions that salt forms with water are very weak.”Of course, both of you cannot be correct. Whenyou conduct an investigation, your observations donot always confirm your prediction. Sometimes,they show that your hypothesis is incorrect. Aninvestigation that does not support your hypothesisis not a bad investigation or a waste of time. Ithas contributed to your scientific knowledge. Youcan re-evaluate your hypothesis and design a newinvestigation.3.B.4. PlanningYou have been asked to design and carry out theboiling point investigation described in 3.B.3. First,you create an experimental design. To conduct acontrolled experiment that tests your hypothesis, youdecide to change only one variable—the amount ofdissolved salt. This is your independent variable. Youdissolve 5.0 g, 10.0 g, 15.0 g, and 20.0 g samples ofsalt in identical beakers containing exactly 100 mLof water. You also prepare a beaker containing waterwith no salt. Each solution is then heated using thesame hot plate until it boils. A thermometer that issuspended in each solution measures the temperatureat which boiling occurs—the dependent variable.Now consider the equipment and materials youneed. Be sure to include any safety equipment, suchas an apron or eye protection, in your equipment andmaterials list. How will you secure the beaker so thatit doesn’t accidentally fall off the hot plate as it boils?Will you use tap water or distilled water?612 Skills Handbook NEL

You need to write a procedure—a step-by-stepdescription of how you will perform yourinvestigation. A procedure should be written as aseries of numbered steps, with only one instructionper step. For example:1. Wear safety goggles, a protective apron, andheat-resistant gloves.2. Set up the equipment as shown in the diagram.(Include a clearly labelled diagram.)3. Add 100 mL of distilled water to the beaker.4. Add one boiling chip to the beaker to ensurethat the water boils gently and does not bump.5. Dissolve 5.0 g of sodium chloride in the water.6. Set the heating control on the hot plate to 50 %.7. Wait for the mixture to boil.8. Turn off the heat and allow the beaker to cool.9. Repeat steps 3–8 using 10.0 g, 15.0 g, and 20.0 gof sodium chloride.10. Allow the apparatus to cool before dismantling it.11. Once cool, return all equipment to the storagecabinet.Your procedure must be clear enough for someoneelse to follow, and it must explain how you will dealwith each of the variables in your investigation. Thefirst step in a procedure usually refers to any safetyprecautions that need to be addressed, and the laststep relates to any cleanup that needs to be done.Your teacher must approve your procedure and listof equipment and materials before you begin.3.B.5. PerformingAs you carry out an investigation, be sure to followthe steps in the procedure carefully and thoroughly.Check with your teacher if you find that significantalterations to your procedure are required. Use allequipment and materials safely, accurately, and withprecision. Be sure to take detailed, careful notes andto record all of your observations. Record numericaldata in a table.3.B.6. ObservingWhen you observe something, you use your sensesto learn about it. You can also use tools, such as abalance or a microscope. Observations of measuredquantities such as temperature, volume, and mass arecalled quantitative observations. Numerical data fromquantitative observations are usually recorded in datatables or graphs.Other observations describe characteristics thatcannot be expressed in numbers. These are calledqualitative observations (Figure 7). Colour, smell,clarity, and state of matter are common examplesof qualitative observations. Qualitative observationscan be recorded using words, pictures, or labelleddiagrams.Figure 7 Qualitative observations such as a colour change,bubbles, an irritating odour, or a sizzling sound suggest that achemical change is occurring when certain chemicals are mixed.As you work on an investigation, be sure torecord all of your observations, both qualitativeand quantitative, clearly and carefully. If a datatable is appropriate for your investigation, use itto organize your observations and measurements.(See Data Tables and Graphs, page 634.) Include allobservations and measurements in your final labreport or presentation. It is important to remainimpartial when recording observations. Recordexactly what you observe. Observations from anexperiment may not always be what you expectthem to be.NEL3. Scientific Inquiry Skills 613

Scientific DrawingsScientific drawings are done to record observationsas accurately as possible. They are also used tocommunicate, which means that they must be clear,well labelled, and easy to understand. Below aresome tips that will help you produce useful scientificdrawings.Getting StartedThe following materials and ideas will help you getstarted:• Use plain, blank paper. Lines might obscure yourdrawing or make your labels confusing.• Use a sharp pencil rather than a pen or markeras you will probably need to erase parts of yourdrawing and do them over again (Figure 8).• Observe and study your specimen or equipmentcarefully, noting details and proportions, beforeyou begin the drawing.thermometerwater containingsodium chlorideboiling chiphot platebeakerstand withbeaker clampwire gauzeFigure 8 Your drawing of an experimental setup shouldshow how the equipment was assembled.Scale RatioYou may want to indicate the actual size of yourobject on your drawing. To do this, use a ratiocalled the scale ratio.• If your diagram is 10 times larger than thereal object (e.g., a tiny organism), your scaleratio is 10×.size of drawing• In general, scale ratio = ​ ________________actual size of object ​You can also show the actual size of the object onyour diagram (Figure 9).actual size, 5 cmFigure 9 This is an example of a scientific drawing thatindicates the actual size of the object.Checklist for Scientific DrawingUse plain, blank (unlined) paper and a sharp, hardpencil.Draw as large as necessary to show details clearly.Do not shade or colour.Draw label lines that are straight and run outsideyour drawing. Use a ruler.Include labels, a title or caption, and, if appropriate,the magnification of the microscope you are using.• Create drawings large enough to show details. Forexample, a third of a page might be appropriatefor a diagram CSH-F54C-SHOS10SB.aiof a single cell or a unicellularorganism. When drawing lab equipment, do notinclude unnecessary details.• Label your diagram clearly. Use a ruler to drawthe label lines.B614 Skills Handbook NEL

3.B.7. AnalyzingYou analyze data from an investigation to make senseof it. You examine and compare the measurementsyou have made. You look for patterns andrelationships that will help you explain your resultsand give you new information about the question youare investigating.Once you have analyzed your data, you can tellwhether your prediction or hypothesis is correct. Youcan also write a conclusion that indicates whether ornot the data supports your hypothesis (Figure 10).You may even come up with a new hypothesis thatcan be tested in a new investigation.Figure 10 Students analyze data and make notes about theirobservations in order to find any patterns.3.B.8. EvaluatingHow useful is the evidence from an investigation?You need quality evidence before you can evaluateyour prediction or hypothesis. If the evidence is pooror unreliable, you can identify areas of improvementfor when the investigation is repeated.Below are some things to consider when evaluatingthe results of an investigation:• Plan: Were there any problems with the way youplanned your experiment or your procedure?Did you control for all the variables, except theindependent variable?• Equipment and Materials: Could better ormore accurate equipment have been used?Was something used incorrectly? Did you havedifficulty with a piece of equipment?• Observations: Did you record all the observationsthat you could have? Or did you ignore oroverlook some observations that might have beenimportant?• Skills: Did you have the appropriate skills for theinvestigation? Did you have to use a skill that youwere just beginning to learn?Once you have identified areas in which errorscould have been made, you can judge the quality ofyour evidence.NEL3. Scientific Inquiry Skills 615

3.B.9. CommunicatingWhen you plan and carry out your own investigation, it is important toshare both your process and your findings. Other people may want torepeat your investigation, or they may want to use or apply your findingsin another situation. Your write-up or report should reflect the process ofscientific inquiry that you used in your investigation.SAMPLE LAB REPORTWrite the title of yourinvestigation at the top ofthe page.List the question(s) you aretrying to answer. This sectionshould be written in sentences.Write your hypothesis orprediction.Write your experimentaldesign, briefly outliningwhat you will be doing andidentifying your independent,dependent, and controlledvariables (if appropriate).Write the equipment (itemsthat can be re-used) andmaterials (substances that willbe used up) in a list. Give theamount or size, if this isimportant. Remember toinclude safety equipment.Raising the Boiling Point of WaterTestable QuestionWhat effect does the mass of sodium chloride have on the boiling point of water?HypothesisIf the amount of sodium chloride is increased, then the boiling point will also increasebecause sodium and chloride ions attract water molecules, preventing them from changinginto gas.Experimental DesignVarious amounts of salt will be added to water to create the same volume of solution.Each solution will be heated and its boiling point measured. The independent variable isthe mass of salt added. The dependent variable is the boiling temperature. The controlledvariables are: type of salt used, equipment used, and volume of solution heated.Equipment and Materialseye protectionlab apronheat-resistant gloves250 mL beakerthermometerwater containingsodium chlorideboiling chiphot platewire gauzeretort stand withbeaker clampbeakerthermometer50 g sodium chloridewaterstand withbeaker clampDraw a large, labelled diagram,if necessary, to show howequipment was set up.boiling chiphot platewire gauzeCSH-F54A-SHOS10SB.aiOntario Science 10 SB0-17-635528-6 616 Skills Handbook NELFNCSH-F54A-SHOS10SB

Procedure1. Safety goggles, a protective apron, and heat resistant gloves were obtained.2. The equipment was set up as shown in the diagram.3. 100 mL distilled water was added to the beaker.4. One boiling chip was added to the beaker to prevent the solution from bumping.5. 5.0 g sodium chloride was dissolved in the water.6. The hot plate heater control was set to 50 %.7. The temperature at which the water boiled was recorded.8. The heat was turned off and the beaker was allowed to cool.9. Steps 3–8 were repeated using 10.0 g, 15.0 g, and 20.0 g of sodium chloride.10. The apparatus was allowed to cool before it was returned.ObservationsTable of ObservationsMass of sodium chloride (g) Boiling point (°C)5 100.410 100.815 101.420 101.8In each case, the water boiled gently. Small bubbles formed throughout the solution asit boiled.Analysis and EvaluationThe boiling point of the solution increased as more salt was dissolved in it. Watercondensing on the thermometer made some of the temperatures difficult to read. Thisproblem could be overcome by using a temperature probe instead of a thermometer.The data clearly support the hypothesis that the boiling point of water increases as themass of dissolved sodium chloride increases.Applications and ExtensionsAdding table salt (sodium chloride) to boiling water does not increase the boiling pointof the water a great deal. Therefore, adding a little salt to boiling water when cookingwill not speed up the cooking process.Describe the procedure usingnumbered steps. Each stepshould start on a new line.Write the steps as theyoccurred, using past tenseand passive voice. Make surethat your steps are clear sothat someone else couldrepeat your investigation.Include any safetyprecautions.Present your observationsin a form that is easilyunderstood. Quantitativeobservations should berecorded in one or more tables,with units included. Qualitativeobservations can be recordedin words or drawings.Analyze your results andevaluate your procedure. Ifyou have created graphs, referto them here. If necessary,include them on a separatepiece of graph paper. Write aconclusion indicating whetheror not your results supportyour hypothesis or prediction.Answer any Analyze andEvaluate questions here.Describe how the knowledgeyou gained from yourinvestigation relates to real-lifesituations. How can thisknowledge be used? Answerany Apply and Extendquestions here.Ontario Science 10 Skills Handbook0-17-635519-7FNNELCSH-F54B-SHOS10SBCSH-F54B-SHOS10SB.ai3. Scientific Inquiry Skills 617

4Research SkillsIn modern society, you are constantly bombardedwith information. Some of this information isreliable, and some is not. Trying to find the “right”information to conduct scientific research may seemoverwhelming. However, the task is less dauntingwhen you learn how to search efficiently for theinformation you need. Then you must know how toassess its credibility. Here are some tips that will helpyou in your research.4.A. General Research Skills4.A.1. Identify the InformationYou Need• Identify your research topic.• Identify the purpose of your research.• Identify what you already know about the topic.• Identify what you do not yet know.• Develop a list of key questions that you need toanswer.• Identify categories based on your key questions.• Use these categories to identify key search words.4.A.2. Identify Sources of InformationIdentify places where you could look for informationabout your topic. These places might includeprograms on television, people in your community,print sources (Figure 1), and electronic sources(such as CD-ROMs and Internet sites).Figure 1 Your school library and local public library are both excellentsources of information.Refer to “Using the Internet” on page 619.Remember, gathering information from a variety ofsources will improve the quality of your research.4.A.3. Evaluate the Sourcesof InformationRead through your sources of information and decidewhether they are useful and reliable. Here are fivethings to consider:• Authority: Who wrote or developed theinformation or who sponsors the website? Whatare the qualifications of this person or group?• Accuracy: Are there any obvious errors orinconsistencies in the information? Does theinformation agree with that of other reliablesources?• Currency: Is the information up to date? Hasrecent scientific information been included?• Suitability: Does the information make sense tosomeone with your experience or of your age?Do you understand it? Is the information wellorganized?• Bias: Are facts reported fairly? Are there reasonswhy your sources might express some bias? Arefacts deliberately left out?4.A.4. Record and Organizethe InformationAfter you have gathered and evaluated your sources ofinformation, you can start organizing your research.Identify categories or headings for note taking. In yournotebook, use point-form notes to record informationin your own words under each heading. You must becareful not to copy information directly from yoursources. If you quote a source, use quotation marks.Record the title, author, publisher, page number, anddate for each of your sources. For websites, recordthe URL (website address). All of these details arenecessary to help you keep track of your sourcesof information so that you can go back to them toclarify any points in the future. You will also need thisinformation to create a bibliography. If necessary, addto your list of questions as you find new information.618 Skills Handbook NEL

To help you organize the information further, youmay want to use pictures, graphic organizers, anddiagrams. (See the Literacy section on page 641.)4.A.5. Make a ConclusionLook at your original research question. What didyou learn from the information you gathered? Canyou state and explain a conclusion based on thatinformation? Do you need further information?If so, where would you look for that information?Do you have an informed opinion on the researchtopic that you did not have before you started? If not,what additional information do you need to reachsuch an opinion?4.A.6. Evaluate Your ResearchNow that your research is complete, reflect onhow you gathered and organized the information(Figure 2). Can you think of ways to improve theresearch process for next time? How valuable werethe sources of information you selected?4.B. Using the InternetThe Internet is a vast and constantly growingnetwork of information. You can use search enginesto help you find what you need, but keep in mindthat not everything you find will be useful, reliable,or true.4.B.1. Search ResultsOnce you have entered your search word or phrase,a list of web page “matches” will appear. If yourkeywords are general, you are likely to get a highnumber of matches. Therefore, you need to refineyour search. Most search engines provide onlinehelp and search tips. Look at these to find ideas forbetter searching.Every web page has a URL (universal resourcelocator). The URL may tell you the name of theorganization hosting the web page, or it may indicatethat you are looking at a personal page (oftenindicated by the ~ character in the URL). The URLalso includes a domain name, which provides cluesabout the organization hosting the web page (Table 1).For example, a URL that includes “ec.gc.ca” indicatesthat the content is hosted by Environment Canada—a reliable source.Table 1 Common URL Codes and OrganizationsFigure 2 Keep track of your sources so you do not forget where youfound your information.4.A.7. Communicate Your ConclusionsChoose a format for communication that suits youraudience, your purpose, and the information yougathered. Are labelled diagrams, graphs, or chartsappropriate?Codecacom or coedu or acorgnetmilgovintOrganizationCanadacommercialeducationalnonprofitnetworking providermilitarygovernmentinternational organizationNEL4. Research Skills 619

4.B.2. Evaluating Internet ResourcesAnyone can post information on the Internetwithout verifying its accuracy. Therefore, you mustlearn to evaluate the information that you findon the Internet as coming from dependable andlegitimate sources.Use the following questions to help determine thequality of an Internet source. The greater the numberof questions answered “yes,” the more likely it is thatthe source is of high quality.• Is it clear who is sponsoring the page? Doesthe site seem to be permanent or sponsoredby a reputable organization?• Is there information about the sponsoringorganization? For example, is a telephonenumber or address given to contact for moreinformation?• Is it clear who developed and wrote theinformation? Are the author’s qualificationsprovided?• Are the sources for factual information givenso that they can be checked?• Are there dates to indicate when the page waswritten, placed online, or last revised?• Is the page presented as a public service? Doesit present balanced points of view?4.B.3. Using School Library ResourcesMany schools and school boards have access toonline encyclopedias with science sections in them.Find out if your school or board has a website whereyou can access these resources. You may need apassword.4.B.4. Using the Nelson WebsiteWhen you see the Nelson Science icon in yourtextbook, you can go to the Nelson website and findlinks to useful sources of information.go to nelson science4.C. Exploring an IssueCriticallyAn issue is a situation in which several points of viewneed to be considered in order to make a decision. Itis often difficult to come to a decision that everyoneagrees with. When a decision affects many people orthe environment, it is important to explore the issuecritically. Think about all the possible solutions andtry to understand all the different perspectives—notjust your own point of view. Consider the risks andbenefits of each possible solution. Put yourself inthe place of several of the stakeholders, to try tounderstand their positions.Exploring an issue critically also means researchingand investigating your ideas and communicating withothers. Figure 3 shows all the steps in the process.Explore an IssueDefining the IssueResearchingIdentifying AlternativesAnalyzing the IssueDefending a DecisionCommunicatingEvaluatingFigure 3 You may perform some or all of these steps as you explorean issue critically.CSH-F20-SHOS10SB.aiNot sure if this is the correct arrow style for flow charts.620 Skills Handbook NEL

4.C.1. Defining the IssueTo explore an issue, first identify what the issueis. An issue has more than one solution, and thereare different points of view about which solution isthe best. Rephrase the issue as a question: “Whatshould …?” The issue can also include informationabout the role a person takes when thinking aboutan issue. For instance, you may think about the issuefrom someone else’s point of view—you may take therole of a landowner, a government worker, or a tourguide. The issue can also include a description ofwho your audience will be—will it be other students,a meeting of government officials, or your parents?Be sure to take into account your role and audiencewhen defining your issue.4.C.2. ResearchingEnsure that the decision you reach is based on agood understanding of the issue. You must be in aposition to choose the most appropriate solution. Todo this, you need to gather factual information thatrepresents all the different points of view. Developgood questions and a plan for your research. Yourresearch may include talking to people, reading aboutthe topic in newspapers and magazines, and doingInternet research.As you collect information, make sure that itis reliable, accurate, and current. Avoid biasedinformation that favours only one side of the issue.It is important to ensure that the information youhave gathered represents all aspects of an issue.Are the sources valuable? Could you find betterinformation elsewhere?4.C.3. Identifying AlternativesConsider possible solutions to the issue. Differentstakeholders may have different ideas on this.Consider all reasonable options. Be creative aboutcombining the suggestions. For example, supposethat your municipal council is trying to decide howto use some vacant land next to your school. You andother students have asked the council to use the landas a nature park. Another group is proposing thatthe land be used to build a seniors’ home becausethere is a shortage of this kind of housing. The schoolboard would like to use the land to build a track forsporting events.After defining the issue and researching, you cannow generate a list of possible solutions. You might,for example, come up with the following choices forthe land-use issue:• Turn the land into a nature park for thecommunity and the school.• Use the land as a playing field and track forthe community and the school.• Create a combination of a nature park and aplaying field.• Use the land to build a seniors’ home witha nature park.4.C.4. Analyzing the IssueDevelop criteria to evaluate each possibility. Forexample, should the solution be the one that has themost community support, or should it be the one thatbest protects the environment? Should it be the leastcostly, financially, or the one that creates the mostjobs? You need to decide which criteria you will useto evaluate the alternatives so that you can decidewhich solution is the best.4.C.5. Defending a DecisionThis is the stage where everyone gets a chance toshare ideas and information gathered about the issue.Then the group needs to evaluate all the possiblealternatives and decide on one solution based onthe criteria.Cost–Benefit AnalysisA cost−benefit analysis can help you determine thebest solution to a complex problem when a numberof solutions are possible. First, research possible costsand benefits associated with a proposed solution.Costs are not always financial. You may be comparingadvantages and disadvantages. Then, based on yourresearch, try to decide the level of importance of eachcost and benefit. This is often a matter of opinion.However, your opinions should be informed byresearched facts.NEL4. Research Skills 621

Once you have completed your research andidentified costs and benefits, you may conduct thecost–benefit analysis as follows:1. Create a table similar to Table 2.2. List costs and benefits.3. Rate each cost and benefit on a scale from 1 to5, where 1 represents the least important cost orbenefit and 5 represents the most important costor benefit.4. After rating each cost and benefit, add up theresults to obtain totals. If the total benefitsoutweigh the total costs, you may decide to goahead with the proposed solution.You could choose one of the following methods ofcommunicating your decision:• Write a report.• Give an oral presentation.• Make a poster.• Prepare a slide show.• Create a video (Figure 4).• Organize a town hall or panel discussion.• Create a blog or webcast.• Write a newspaper article.Table 2 Cost–Benefit Analysis of Using Land to Build a Seniors’Home with a Nature ParkCostsBenefitsPossibleresultCost ofresult(rate 1 to 5)PossibleresultBenefit ofresult(rate 1 to 5)land cannotbe used forsportsexpensive tomaintainnature parkwill be verysmallTotal costvalue2439seniors’ homeprovidesnecessaryhousingpark preservessome habitatfor plants andanimalspark increasesvalue of seniorshomeTotal benefitvalue4.C.6. CommunicatingYou might be told how you will communicate yourdecision. For example, your class might hold a formaldebate. Alternatively, you might be free to chooseyour own method of communication.54312Figure 4 Creating a video is an effective way to communicateinformation about an issue.Choose a type of presentation that will share yourdecision or recommendation in a way that is suitablefor your audience. For example, if your audience issmall, it might be easiest to present your decisionin person. An oral presentation is a good way topresent your decision to many people at one time.If your presentation includes visuals, ensure thatthey are large and clear enough for your audienceto see. Creating a poster or a blog allows people toread your recommendation on their own, but youmust find a way to let others know where to findthis information.622 Skills Handbook NEL

Whatever means you use, however, you should• state your position clearly, considering youraudience;• support it with objective data if possible, andwith a persuasive argument; and• be prepared to defend your position againstopposition (Figure 5).• How did I gather information about theissue? What criteria did I use to evaluate theinformation? How satisfied am I with the qualityof my information?• What information did I consider to be the mostimportant when making my decision?• How did I make my decision? What process didI use? What steps did I follow?• To what extent were my arguments factuallyaccurate and persuasively made? (Figure 6)• In what ways does my decision resolve the issue?• What are the likely short-term and long-termeffects of my decision?• How might my decision affect the variousstakeholders?• To what extent am I satisfied with my decision?• If I had to make this decision again, what wouldI do differently?Figure 5 Share your information in a way that makes it easy for youraudience to understand.4.C.7. EvaluatingThe final step of the decision-making process includesevaluating the decision itself and the process used toreach the decision. After you have made a decision,carefully examine the thinking that led to thisdecision. Some questions to guide your evaluationinclude the following:• What was my initial perspective on the issue?How has my perspective changed since I firstbegan to explore the issue?Figure 6 Were the arguments clearly presented and backed up byevidence?NEL4. Research Skills 623

5Using Mathematics in ScienceEffective communication of experimental data is animportant part of science. To avoid confusion whenreporting measurements or using measurements incalculations, there are a few accepted conventionsand practices that should be followed.5.A. SI UnitsThe scientific communities of many countries,including Canada, have agreed on a system ofmeasurement called SI (Système internationald’unités). This system consists of the sevenfundamental SI units, called base units, shownin Table 1.Table 1 The Seven SI Base UnitsQuantity name Unit name Unit symbollength metre mmass kilogram kg*time second selectric current ampere Atemperature kelvin K**amount of substance mole mollight intensity candela cd*The kilogram is the only base unit that contains a prefix.**Although the base unit for temperature is a kelvin (K), the common unit fortemperature is a degree Celsius (°C).All other physical quantities can be expressedas a combination of these seven SI base units. Forexample, the speed of an object is determined bythe distance it travels in a specified time period.Therefore, the unit for speed is metres (distance) persecond (time) or m/s. Units that are formed usingtwo or more base units are called derived units. Somederived units have special names and symbols. Forexample, the unit of force that causes a mass of 1 kgto accelerate at a rate of 1 m/s 2 (metre per second persecond) is known as a newton (N). In base units, thenewton is m·kg/s 2 . The dot between m and kg means“multiplied by,” but m·kg is simply read as “metrekilogram.” The slash means “divided by” and is read“per.” The whole unit is read “metre kilogram persecond squared.” You can see why a special nameand symbol are given to some derived units.Some common quantities and their units are listedin Table 2. Note that the symbols representing thequantities are italicized, whereas the unit symbolsare not.Table 2 Common Quantities and UnitsQuantity nameQuantitysymbolUnit nameUnitsymboldistance d metre marea A square metre m 2volumeVcubic metre m 3litrespeed v metre per second m/sacceleration a metre per secondper second5.A.1 Converting UnitsAn important feature of SI is the use of prefixesto express small or large sizes of any quantityconveniently. SI prefixes act as multipliers to increaseor decrease the value of a number in multiples of10 (Table 3). The most common prefixes change thesize in multiples of 1000 (10 3 or 10 −3 ), except forcenti (10 −2 ), as in centimetre.Lm/s 2concentration c gram per litre g/Ltemperature t degree Celsius °Cpressure p pascal Paenergy E joule Jwork W joule Jpower P watt Welectric potential V volt VelectricalresistanceR ohm Ωcurrent I ampere A624 Skills Handbook NEL

SI prefixes are also used to create conversionMultiplying by a conversion factor is likefactors (ratios) to convert between larger or smaller multiplying by 1: it does not change the quantity,values of a unit. For example,only the unit in which it is expressed. Let’s see howto convert from one unit to another.1 km = 1000 mTherefore, ______ 1kg 000 g​ ​= ​1 ______1 000 g 1 kg ​= 1Table 3 Common SI PrefixesPrefix Symbol Factor by which unit is multiplied Examplegiga G 1 000 000 000 1 000 000 000 m = 1 Gmmega M 1 000 000 1 000 000 m = 1 Mmkilo k 1 000 1 000 m = 1 kmhecto h 100 100 m = 1 hmdeca da 10 10 m = 1 damdeci d 0.1 0.1 m = 1 dmcenti c 0.01 0.01 m = 1 cmmilli m 0.001 0.001 m = 1 mmmicro μ 0.000 001 0.000 001 m = 1 μmnano n 0.000 000 001 0.000 000 001 m = 1 nm1Sample Problem 1 Using Conversion FactorsA block of cheese at a grocery store has a mass of 1 256 g. Its price is $15.00/kg. What is theprice of the block of cheese?First, convert the mass from grams to kilograms.There are two possible conversion factors between g and kg, as shown above.Always choose the conversion factor that cancels the original unit. In this case, the originalunit is g, so the correct conversion factor is ​ ______ 1 kg1 000 g ​1 256 g = ​______1 kgThe original units, g, cancel (divide to give 1), leaving kg as the new unit.Now that you have determined the mass in kg, multiply the price per kg by the mass in kg.$15.00/kg × 1.256 kg = $18.84The price of the block of cheese is $18.84.1 000 g ​= 1.256 kg 5. Using Mathematics in Science 625practiceConversionsMake the following conversions. Refer to Table 3if necessary.(a) Write 3.5 s in ms.(b) Change 5.2 A to mA.(c) Convert 7.5 µg to ng.Convenient conversion factors to convert betweenmillimetres and metres are​1 _________ 000 mm1 m ​ and ​ _________ 1 m1 000 mm ​Conversion factors can be used for any unitequality, such as 1 h = 60 min and 1 min = 60 s.NEL

5.B. Solving NumericalProblems Using the GRASSMethodIn science and technology, you sometimes haveproblems that involve quantities (numbers), units,and mathematical equations. An effective method forsolving these problems is the GRASS method. Thisalways involves five steps: Given, Required, Analysis,Solution, and Statement.Given: Read the problem carefully and list all ofthe values that are given. Remember to include units.Required: Read the problem again and identify thevalue that the question is asking you to find.Analysis: Read the problem again and thinkabout the relationship between the given values andthe required value. There may be a mathematicalequation you could use to calculate the required valueusing the given values. If so, write the equation downin this step. Sometimes it helps to sketch a diagram ofthe problem.Solution: Use the equation you identified in the“Analysis” step to solve the problem. Usually, yousubstitute the given values into the equation andcalculate the required value. Do not forget to includeunits and to round off your answer to an appropriatenumber of digits. (See Sections 5.C. and 5.D. onsignificant digits and scientific notation for help.)Statement: Write a sentence that describesyour answer to the question you identified in the“Required” step.Sometimes two of these steps can be addressedtogether. (See Sample Problem 2 below).5.C. Scientific NotationScientists often work with very large or very smallnumbers. Such numbers are difficult to work with whenthey are written in common decimal notation. Forexample, the speed of light is about 300 000 000 m/s.There are many zeros to keep track of if you have tomultiply or divide this number by another number.Sometimes it is possible to change a very large orvery small number, so that the number falls between0.1 and 1000, by changing the SI prefix. For example,237 000 000 mm can be converted to 237 km, and0.000 895 kg can be expressed as 895 mg.Alternatively, very large or very small numberscan be written using scientific notation. Scientificnotation expresses a number by writing it in theform a × 1​0​n​, where the letter a, referred to as thecoefficient, is a value that is at least 1 and less than10. The number 10 is the base, and n represents theexponent. The base and the exponent are read as “10to the power of n.” Powers of 10 and their decimalequivalents are shown in Table 4 on page 627.Sample Problem 2 Locating the ImageA small toy building block is placed 7.2 cm in front of a lens. An upright, virtual image ofmagnification 3.2 is noticed. Where is the image located?Given:d 0= 7.2 cmM = 3.2Required: d 1= ?Analysis and Solution: M = ___ ​ −d 1​d 0−Md 0= d 1d 1= −Md 1= −(3.2)(7.2 cm)Statement:d 1= −23 cmThe image of the toy block is located 23 cm from the lens, on thesame side as the object.626 Skills Handbook NEL

Table 4 Powers of 10 and Decimal EquivalentsPower of 10Decimal equivalent1​0​ 9 ​ 1 000 000 000​10​ 8 ​ 100 000 000​10​ 7 ​ 10 000 000​10​ 6 ​ 1 000 000​10​ 5 ​ 100 000​10​ 4 ​ 10 000​10​ 3 ​ 1 000​10​ 2 ​ 100​10​ 1 ​ 10​10​ 0 ​ 1​10​ −1 ​ 0.1​10​ −2 ​ 0.01​10​ −3 ​ 0.001​10​ −4 ​ 0.000 1​10​ −5 ​ 0.000 01​10​ −6 ​ 0.000 001​10​ −7 ​ 0.000 000 1​10​ −8 ​ 0.000 000 01​10​ −9 ​ 0.000 000 001To write a large number in scientific notation,follow these steps:1. To determine the exponent, count the numberof places you have to move the decimal pointto the left, to give a number between 1 and 10.For example, when writing the speed of light(300 000 000 m/s) in scientific notation, you haveto move the decimal point eight places to the left.The exponent is therefore 8.2. To form the coefficient, place the decimal pointafter the first digit. Now drop all the trailing zerosunless all the numbers after the decimal are zeros,in which case, keep one zero. In our example, thecoefficient is 3.0.3. Combine the coefficient with the base, 10, andthe exponent. For example, the speed of light is3.0 × 1​0​ 8 ​m/s.Very small numbers (less than 1) can also beexpressed in scientific notation. To find the exponent,count the number of places you move the decimalpoint to the right, to give a coefficient between 1 and10. For very small numbers, the base (10) must begiven a negative exponent.For example, a millionth of a second, 0.000 001 s,can be written in scientific notation as 1 × 1​0​ −6 ​s.Table 5 shows several examples of large and smallnumbers expressed in scientific notation.To multiply numbers in scientific notation, multiplythe coefficients and add the exponents. For example,(3 × 1​0​ 3 ​)(5 × ​10​ 4 ​) = 15 × ​10​ 3 + 4 ​= 15 × 1​0​ 7 ​= 1.5 × 1​0​ 8 ​Note that when writing a number in scientificnotation, the coefficient should be at least 1 and lessthan 10.When dividing numbers in scientific notation,divide the coefficients and subtract the exponents.For example,​ 8 ______ × 1​0​6 ​2 × 1​0​ 4 ​ ​= 4 × 1​0​6−4 ​= 4 × 1​0​ 2 ​Table 5 Numbers Expressed in Scientific NotationLarge or small number Common decimal notation Scientific notation124.5 million km 124 500 000 km 1.245 × 1​0​ 8 ​ km154 thousand nm 154 000 nm 1.54 × 1​0​ 5 ​ nm753 trillionths of a kg 0.000 000 000 753 kg 7.53 × 1​0​ −10 ​ kg315 billionths of a m 0.000 000 315 m 3.15 × ​10​ −7 ​ mNEL5. Using Mathematics in Science 627

5.D. Uncertainty inMeasurementThere are two types of quantities used in science: exactvalues and measurements. Exact values include definedquantities: those obtained from SI prefix definitions(such as 1 km = 1000 m) and those obtained fromother definitions (such as 1 h = 60 min).Exact values also include counted values, such as5 beakers or 10 cells. All exact values are consideredcompletely certain. In other words, 1 km is exactly1000 m, not 999.9 m or 1000.2 m. Similarly, 5 beakerscould not be 4.9 or 5.1 beakers; 5 beakers are exactly5 beakers.Measurements, however, have some uncertainty.The uncertainty depends on the limitations of theparticular measuring instrument used and the skillof the measurer.5.D.1. Significant DigitsThe certainty of any measurement is communicated bythe number of significant digits in the measurement.In a measured or calculated value, significant digitsare the digits that are certain, plus one estimated(uncertain) digit. Significant digits include all thedigits that are correctly reported from a measurement.For example, 10 different people independentlyreading the water volume in the graduated cylinder inFigure 1 would all agree that the volume is atleast 50 mL. In other words, the “5” is certain.However, there is some uncertainty in the nextdigit. The observers might report the volume asbeing 56 mL, 57 mL, or 58 mL. The only way to knowfor sure is to measure with a more precise measuringdevice. Therefore, we say that a measurement such as57 mL has two significant digits: one that is certain(5) and the other that is uncertain (7). The last digitin a measurement is always the uncertain digit. Forexample, 115.6 g contains three certain digits (115)and one uncertain digit (6).100 mL908070605040302010volume of waterand solidvolume of water100 mLvolumeof solidFigure 1 This figure shows the difficulty of making observationsusing an imprecise measuring device.Table 6 provides the guidelines for determining thenumber of significant digits, along with examples toillustrate each guideline.908070605040302010Table 6 Guidelines for Determining Significant DigitsGuidelineCount from left to right, beginning with the first non-zero digit.Zeros at the beginning of a number are never significant.All non-zero digits in a number are significant.Zeros between digits are significant.Zeros at the end of a number with a decimal point are significant.Zeros at the end of a number without a decimal point are ambiguous.All digits in the coefficient of a number written in scientific notation are significant.ExampleNumber Number of significant digits345 3457.35 50.235 30.003 11.1223 476.2 2107.05 50.02094 410.0 3303.0 45400 at least 2200 000 at least 15.4 × 1​0​ 3 ​ 25.40 × 1​0​ 3 ​ 35.400 × ​10​ 3 ​ 4628 Skills Handbook NEL

RoundingUse these rules when rounding answers to the correctnumber of significant digits:1. When the first digit discarded is less than 5, thelast digit kept (i.e., the one before the discardeddigit) should not be changed.Example:3.141 326 rounded to four digits is 3.141.2. When the first digit discarded is greater than 5,or when it is 5 followed by at least one digit otherthan zero, the last digit kept is increased by oneunit.Examples:2.221 372 rounded to five digits is 2.2214.4.168 501 rounded to four digits is 4.169.3. When the first digit discarded is 5 followed byonly zeros, the last digit kept is increased by 1 ifit is odd but not changed if it is even. Note thatwhen this rule is followed, the last digit in thefinal number is always even.Examples:2.35 rounded to two digits is 2.42.45 rounded to two digits is 2.46.75 rounded to two digits is 6.84. When adding or subtracting measured quantities,look for the quantity with the fewest numberof digits to the right of the decimal point. Theanswer can have no more digits to the right ofthe decimal point than this quantity has. In otherwords, the answer cannot be more precise thanthe least precise value.Example:12.52 g+ 349.0 g+ 8.24 g369.76 gBecause 349.0 g is the quantity with the fewestdigits to the right of the decimal point, the answermust be rounded to 369.8 g.Example:157.85 mL− 32.4 mL125.45 mLBecause 32.4 mL has the fewest decimal places,the answer must be rounded to 125.4 mL. Notethat Rule 3 applies.NEL5. When multiplying or dividing, the answer mustcontain no more significant digits than thequantity with the fewest number of significantdigits.Examples:m = ​_____1.15 gc​m​ 3 ​ ​× 16 c​m​3 ​= 18 g∆t = 1.25 h × ​ ______ 60 min​= 75.0 min1 hIn other words, the answer cannot be more certainthan the least certain value.Note, in the second example, 1.25 h is ameasurement and, as a result, contains uncertainty.However, 60 min/h is an exact quantity. Since ithas no uncertainty, the number of significant digitsin the final answer is based only on the measuredvalue of 1.25 h.Rule 5 also applies when multiplying or dividingmeasurements expressed in scientific notation. Forexample,(3.5 × 10 3 ​km)(7.4 × 1​0 2 ​km) = 25.9 × 1​0 5 ​ k​m 2 ​= 2.59 × 1​0​ 6 ​ k​m 2 ​ ​= 2.6 × 1​0 6 ​ k​m 2 ​The coefficient should be rounded to the samenumber of significant digits as the measurementwith the least number of significant digits (the leastcertain value). In this example, both measurementshave only two significant digits, so the coefficient2.59 should be rounded to 2.6 to give a finalanswer of 2.6 × 1​0​ 6 ​ k ​m 2 ​ ​.Similarly,3.9 × 1​0 6 ​ m__________5.3 × 1​0 3 ​ s ​ = 0.7377 × 1​03 ​m/s= 7.377 × 1​0 2 ​m/s= 7.4 × 1​0 2 ​m/s5. Using Mathematics in Science 629

5.D.2. Measurement ErrorsThere are two types of error that can occur whenmeasurements are taken: random and systematic.Random error results when an estimate is made toobtain the last significant digit for a measurement.The size of the random error is determined by theprecision of the measuring instrument. For example,when measuring length, it is necessary to estimatebetween the marks on the measuring tape. If thesemarks are 1 cm apart, the random error is greater andthe precision is less than if the marks were 1 mmapart. Systematic error is caused by a problem withthe measuring system itself, such as equipmentnot set up correctly. For example, if a balance isnot tared (re-set to zero) at the beginning, all themeasurements taken with the balance will have asystematic error.The precision of measurements depends on themarkings (gradations) of the measuring device.Precision is the place value of the last measurabledigit. For example, a measurement of 12.74 cmis more precise than a measurement of 127.4 cmbecause 12.74 was measured to hundredths of acentimetre, whereas 127.4 was measured to tenths ofa centimetre.When adding or subtracting measurements withdifferent precisions, round the answer to the sameprecision as the least precise measurement. Considerthe following:11.7 cm3.29 cm+ 0.542 cm15.532 cmThe first measurement, 11.7 cm, is measured toone decimal place and is the least precise. The answermust be rounded to one decimal place, or 15.5 cm.No matter how precise a measurement is, it stillmay not be accurate. Accuracy refers to how close avalue is to its accepted value. Figure 2 uses the resultsof a horseshoe game to explain precision and accuracy.(a) precise and accurate(c) accurate but not precise(b) precise but not accurate(d) neither accurate nor preciseFigure 2 The patterns of the horseshoes illustrate the comparisonbetween accuracy and precision.How certain you are about a measurement dependson two factors: the precision of the instrumentand the size of the measured quantity. Instrumentsthat are more precise give more certain values. Forexample, a measurement of 13 g is less precise thanone of 12.76 g because the second measurement hasmore decimal places than the first. Certainty alsodepends on the size of the measurement. For example,consider the measurements 0.4 cm and 15.9 cm.Both have the same precision (number of decimalplaces): both are measured to the nearest tenth of acentimetre. Imagine that the measuring instrumentis precise to ± 0.1 cm, however. An error of 0.1 cm ismuch more significant for the 0.4 cm measurementthan it is for the 15.9 cm measurement because thesecond measurement is much larger than the first. Forboth factors—the precision of the instrument usedand the value of the measured quantity—the moredigits there are in a measurement, the more certainyou are about the measurement.630 Skills Handbook NEL

5.E. Using the CalculatorA calculator is a very useful device that makescalculations easier, faster, and probably moreaccurate. However, like any other electronicinstrument, you need to learn how to use it. Theseguidelines apply to a basic scientific calculator.If your calculator is different, such as a graphingcalculator, some of the instructions and operationsmay use different keys or sequences, so alwayscheck the manual.General Points• Most calculators follow the usual mathematicalrules for order of operations—multiplication/division before addition/subtraction. For example,if you are calculating y using y = mx + b, youcan enter the values of m times x plus b in onesequence. The calculator will “know” that m and xmust be multiplied first before b is added.• Calculators do not keep track of significantdigits. For example, 12.0 is the same as 12 for acalculator.• Some calculator keys such asx 2• Do not clear all numbers CSH-F25-SHOS10SB.aifrom theCSH-F27-SHOS10SB.aicalculatorCSH-F24-SHOS10SB.aiuntil CSH-F26-SHOS10SB.aiyou are completely finished with a question:the result of one calculation can be reused to startthe next one.• All scientific calculators have at least one memoryOntario Science 10 Skills Handbooklocation where you can store a number (M+ and0-17-635519-7STO are common keys) and recall it later (usuallywith MR or RCL). UseFNCSH-F28-SHOS10SBit to avoid re-enteringmany digits.COCrowleArt GroupOntario Science 10 Skills HandbookDeborah CrowleScience 10 Skills Handbook0-17-635519-7Pass2nd pass519-7 ookFNCSH-F27-SHOS10SB ApprovedCSH-F25-SHOS10SBCOCrowleArt Group Not Approved10SB CrowleArt GroupDeborah Crowleup Deborah CrowlePass2nd passle 2nd passApproveddNot ApprovedrovedNEL1— x√ x )+/– , , (and its second function,apply the operation only to the value in thedisplay regardless of other operations in progress.This means you can quickly change the sign ofthe number, convert to the reciprocal, squarethe number, or determine the square root whileinputting a sequence of calculations.Multiplication and Division• Division is the inverse of multiplication.This means that dividing by a number is theequivalent to multiplying by the inverse of thesame number. For example,​ ______ 12 km0.75 h ​is the same as 12 km × _____ ​ 10.75 h ​and equals 16 ___ ​ kmh ​.This is particularly useful when you want todivide by a number that is currently in the display ofyour calculator. For example, you have just finishedconverting 45 min to 0.75 h in your calculator andnow you want to calculate the speed.Display: 0.75Press:1 —x × 1 = 2New display: 16• Brackets, ( ), are useful to force the calculatorto perform the operation(s) inside the bracketsfirst, before continuing with the calculation.The calculation of the slope of a line is a goodexample.slope = ___ ​ ∆d∆t ​CSH-F28-SHOS10SB.ai(15.2 − 4.1) m= ​ ____________(6.5 − 3.6) s ​= 3.8 ​ m__ s ​If you do not use the brackets on your calculator,you will have to calculate the numerator anddenominator separately and then divide.5. Using Mathematics in Science 631

Scientific NotationOn many calculators, scientific notation is enteredusing a special key, labelled EXP or EE. This keyincludes “×10” from the scientific notation, and youneed to enter only the exponent. For example, toenter7.5 × 10 4 press7 . 5 EXP 43.6 × 10 –3 press 3 . 6 EXP +/– 3Calculating a MeanThere are many statistical methods of analyzingexperimental evidence. One of the most commonand important is calculating an arithmetic mean,or simply a mean. The mean of a set of values is thesum of all reasonable values divided by the totalnumber of values. (This is also commonly knownCSH-F29-SHOS10SB.aias the average of a set of values, but this term is notrecommended because it is too vague and open todifferent interpretations.)Suppose you measure the root growth of fiveseedlings. Your root measurements after three daysare 1.7 mm, 1.6 mm, 1.8 mm, 0.4 mm, and 1.6 mm.What is the mean root growth? Inspection of themeasurements shows that the 0.4 mm measurementclearly does not fit with the rest. Perhaps this seedlingwas infected with a fungus, or some other problemoccurred. You should not include this result in yours Handbook mean but leave it in your evidence table so everyonecan see the decision that you made. Using only9-SHOS10SBreasonable values,Art Group mean root growth = 1.7 mm + 1.6 mm + 1.8 mm + 1.6 mmah Crowle= 1.7 mmsMeans are important in all areas of science becausemultiple measurements or trials are widely used toincrease the reliability of the results.EquationsAlgebra is a set of rules and procedures for workingwith mathematical equations. In general, yourequations will contain one unknown quantity.Whatever mathematical operation is performedto one side of an equation must be performed tothe other side. To solve for an unknown value, youneed to isolate it on one side of the equal sign. Toaccomplish this, you should follow three rules:1. The same quantity can be added or subtractedfrom both sides of the equation without changingthe equality.The following examples illustrate this rule:100 m = 100 m x + b = y100 m − 5 m = 100 m − 5 m x + b − b = y − b95 m = 95 m x = y − bThe example on the left shows the applicationof this rule using quantities with numbers andunits. The rule works equally well with quantitysymbols. The example on the right shows how toisolate x.2. The same quantity can be multiplied or dividedon both sides of the equation without changingthe equality.The following examples illustrate this rule. Theexample on the left shows the use of this rulewith known quantities. Use the same rule withan equation containing quantity symbols toisolate one of the quantities. To solve for d in theexample on the right, multiply both sides by t.Notice that t divided by t equals 1. Multiplying ordividing any quantity by 1 does not change thequantity; therefore, d × 1 = d.120 m = 120 m v = ​ d__t ​​ ______ 120 8.0 ms = ​120 ______8.0 ms ​ v × t = __ ​d t ​ × t15 m/s = 15 m/s vt = d or d = vt632 Skills Handbook NEL

3. The same power (such as square or square root)can be applied to both sides of the equationwithout changing the equality.The following examples illustrate this rule:25 ​s​ 2 ​= 25 ​s​ 2 ​b​ 2 ​ = A​√ ____25 ​s​ 2 ​= ​√ ____25 ​s​ 2 √ __​b​ 2 ​= ​√ __A ​5.0 s = 5.0 s b = ​√ __A ​If several of the rules listed above are requiredto isolate an unknown quantity, then you shouldapply Rule 1 first, whenever possible, and thenapply Rule 2. In general, Rule 3 should be usedlast.5.F. Working with AnglesMeasuring angles is an important skill in the studyof optics. The angle at which a light ray strikesa reflecting surface is usually measured from aperpendicular reference line called a normal. Aprotractor is used to measure the angle that anincoming (or incident) light ray makes relative to thenormal (Figure 3).Sine of an AngleYou may be required to determine the sine of anangle. Sine is a specific mathematical function thatyou will learn more about in future science and mathcourses. For now, all you need to know is how tocalculate the sine of an angle using your calculator.The sequence of buttons to press to determinethe sine of an angle varies with the model of thecalculator. However, these steps work for mostcommon calculators:• Make sure that the calculator is in “degree” mode.(Check the manual if you are unsure.)• Press the “sin” button.• Enter the angle (e.g., 30).• Press the equal button.The sine of 30° is 0.5.practiceSines of AnglesDetermine the sine of the following angles:(a) 45° (b) 60° (c) 64° (d) 90°reflected light ray20100301601701804015050140601301207011080normal10030°901008030°1107090°12060130501404015030incident light ray20101600170180protractormirrorFigure 3 Angles are measured from the normal using a protractor.Inverse SineSometimes you will be given the sine of an angle andbe asked to determine the angle.Given the sine of an angle, you can also solve forthe angle. Follow these steps:• Make sure that the calculator is in “degree” mode.• Press the shift “sin −1 ” buttons.• Enter the value (e.g., 0.5).• Press the equal button.The angle whose sine equals 0.5 is 30°.practiceAngles of SinesDetermine the angles that have the following sines:(e) 0.7071 (f) 0.8660 (g) 0.8988 (h) 1CSH-F31-SHOS10SB.aiNEL5. Using Mathematics in Science 633

6Data Tables and GraphsData tables are an effective means of recording bothqualitative and quantitative observations. Makinga data table should be one of your first steps as youprepare to conduct an investigation. It is particularlyuseful for recording the values of the independentvariable (the cause) and the dependent variables (theeffects), as shown in Table 1.Table 1 A Running White-Tailed DeerTime (s)Distance (m)0 01.0 132.0 253.0 404.0 515.0 666.0 78Follow these guidelines to make a data table:• Use a ruler to make your table.• Write a title that precisely describes your data.• Include the units of measurement for eachvariable, when appropriate.• List the values of the independent variable in theleft-hand column.• List the values of the dependent variable(s) in thecolumn(s) to the right.6.A. Graphing DataA graph is a visual representation of quantitative data.Graphing data often makes it easier to identify a trendor pattern in the data, which indicates a relationshipbetween the variables. There are many types of graphsthat can be used to organize data. Three of the mostuseful kinds of graphs are bar graphs, circle graphs,and point-and-line graphs. Each kind of graph hasits own special uses. You need to identify which typeof graph is most appropriate for the data you havecollected. Then you can construct the graph.Bar GraphsA bar graph helps you make comparisons when onevariable is in numbers (e.g., rainfall) and the othervariable is not (e.g., month of the year). Figure 1shows a bar graph of the distribution of rainfall overa 12-month period in Ottawa. Each bar stands for adifferent month. This graph clearly shows that rainfallis higher in the summer months and is lower in thewinter months.Rainfall (mm)100908070605040302010Average Rainfall in OttawaJ F M A M J J A S O N DMonthFigure 1 A bar graphCircle GraphsCircle graphs (pie charts) are useful to show howthe whole of something is divided into many parts.For example, the circle graph in Figure 2 shows thattransportation is the largest source of greenhouse gasemissions by individuals.Individual Greenhouse Gas EmissionsIndividual Greenhouse Gas Emissionswater heating 7 %water heating garbage 9 %garbage appliancesandapplianceslights 6 %and lights Figure 2 A circle graphhomeheatinghomeandheatingcoolingandcooling22 %22 transportationtransportation56 %56 Point-and-Line GraphsWhen both variables are quantitative, use a pointand-linegraph. This format shows all the data pointsand a line of best fit indicating any relationship634 Skills Handbook NEL

etween the variables. For example, we can usethe following guidelines and the data in Table 1 toconstruct the line graph in Figure 3.Distance (m)8070605040302010A Running White-Tailed Deer00 1 2 3 4 5 6Time (s)Figure 3 A point-and-line graph of the data from Table 1Making Point-and-Line Graphs1. Use graph paper. Draw a horizontal line close tothe bottom of the paper as the x-axis and a verticalline close to the left edge as the y-axis.2. You will generally plot the independent variablealong the x-axis and the dependent variable alongthe y-axis. The exception is when one variable istime: always plot time on the x-axis. The slope ofthe graph then always represents a rate. Label eachaxis, including the units.3. Give your graph a title: a short, accuratedescription of the data represented by the graph.4. Determine the range of values for each variable.The range is the difference between the greatestand least values. Graphs often include a little extralength on each axis.5. Choose a scale for each axis. The scale will dependon how much space you have and the range ofvalues for each axis. Spaces on the grid usuallyrepresent equal increments, such as 1, 2, 5, 10,or 100.6. Plot the points. In Figure 3, the first set of pointsis 0 on the x-axis and 0 on the y-axis: the origin.7. After all the points are plotted, try to visualize aline through the points to show the relationshipbetween the variables. Not all points may lieexactly on a line. Draw the line of best fit—astraight or smoothly curving line through thepoints so that there is approximately the sameNELnumber of points on each side of the line. The line’spurpose is to show the overall pattern of the data.8. If you are plotting more than one set of data onthe same graph, use different colours or symbolsfor each. Provide a legend.Calculating SlopesIf the line of best fit on a graph is a straight line,there is a simple relationship between the twovariables. You can represent this linear (straight-line)relationship with this mathematical equation:y = mx + bwhere y is the dependent variable (on the y-axis), xis the independent variable (on the x-axis), m is theslope of the line, and b is the y-intercept (the pointwhere the line touches the y-axis). To determine theslope, choose two points on the line, (x 1, y 1) and (x 2,y 2). (Note that these are not necessarily data points:just two points on the line.) The slope is equal tom = ​ ____ run rise ​= ​y ______− y 2 1x 2− x ​1For the graph in Figure 4, suppose you choose thetwo points (1.5, 20) and (5.5, 72). You can use themto calculate the slope.m = ​______y − y 2 1x 2− x ​1= ​72 ___________ m − 20 m5.5 s − 1.5 s ​= ​_____524.0 ms ​= 13 m/sThe slope of the line is 13 m/s. The positivenumber indicates a direct relationship.A Running White-Tailed Deer80Distance (m)70605040302010rise = 72m – 20mrun = 5.5s – 1.5s0 1 2 3 4 5 6Time (s)Figure 4 Calculating the slope of a line of best fit6. Data Tables and Graphs 635

6.B. Using Computers forGraphingYou can use spreadsheet or graphing programs onyour computer to construct bar, circle, and pointand-linegraphs. In addition, such programs can usestatistical analysis to compute the line of best fit. Thefollowing instructions guide you to produce best-fitline graph values for two variables on a spreadsheet.Steps for Creating a Graph in aSpreadsheet Program1. Start the spreadsheet program. Enter the data withthe values for x (the first column in your datatable) that start in cell A2. Now enter the valuesfor y from the other column that start in B2.2. Highlight the two columns containing your data(A2 … B6). From the toolbar, select the buttonfor creating graphs. The cursor may change to asymbol, which allows you to “click and drag” tochoose the size of your graph.3. A series of choices will now be presented to you,so you can specify what kind of graph you wantto create. A scatter graph is most appropriate forour data.• Click in the “Title” box and type the title of thegraph.• Click in “Value (X)” box and type the label andunits for the x-axis.• Click the “Finish” button.4. To add a line of best fit, point your cursor to oneof the highlighted data points and right clickonce. Select the “Trendline” option. Make surethat the “Linear” box is highlighted under Type.5. To find the slope or y-intercept, click on the“Options” tab and select the box beside “DisplayEquation on Chart.” This will put the values fory = mx + b on the graph, giving you the slope andy-intercept value.6. Save your spreadsheet before you close theprogram.6.C. Interpreting GraphsWhen data from an investigation are plotted on anappropriate graph, patterns and relationships becomeeasier to see and interpret. You can more easily tell ifthe data support your hypothesis. Looking at the datain the graph may also lead you to a new hypothesis.Or you can extract meaning from other people’sinvestigations.What to Look for When Reading GraphsHere are some questions to help you interpret a graph:• What variables are represented?• What is the dependent variable? What is theindependent variable?• Are the variables quantitative or qualitative?• If the data are quantitative, what are the units ofmeasurement?• What do the highest and lowest values representon the graph?• What is the range between the highest and thelowest values on each axis?• Are the axes continuous? Do they start at zero?• What patterns or trends exist between thevariables?• If there is a linear relationship, what might theslope of the line tell you?Using Graphs for PredictingIf a graph shows a regular pattern, you can use itto make predictions. For example, you could usethe graph in Figure 3 on page 635 to predict thedistance travelled by the deer in 8.0 s. To do this, youextrapolate the graph (extended beyond the measuredpoints), assuming that the observed trend wouldcontinue. You should be careful when predictingvalues outside of your measured range. The fartheryou are from the known values, the less reliable willbe your prediction.636 Skills Handbook NEL

Study Skills77.A. Working TogetherTeamwork is just as important in science as it is on theplaying field or in the gym. Scientific investigationsare usually carried out by teams of people workingtogether. Ideas are shared, experiments are designed,data are analyzed, and results are evaluated and sharedwith other investigators. Group work is necessary andis usually more productive than working alone.Several times throughout the year, you may beasked to work with one or more of your classmates.Whatever the task that your group is assigned, youneed to follow a few guidelines to ensure a productiveand successful experience.7.A.1. General Guidelines forEffective Teamwork• Keep an open mind. Everyone’s ideas deserveconsideration.• Divide the task among all the group members.Choose a role best suited to your particularstrengths.• Work together and take turns. Encourage, listen,clarify, help, and trust one another.• Remember that the success of the team iseveryone’s responsibility. Every member needs tobe able to demonstrate what the team has learnedand support the team’s final decision.7.A.2. Exchanging Information OrallyYou will be involved in a number of differentactivities during your science course. These activitieshelp you express your ideas and learn about newones. Here are three of the more successful discussionformats that your group may use to share ideas:• In a think-pair-share activity, you and yourpartner are given a problem. Each of youdevelops a response (usually within a time limit).Then share your ideas with each other to resolvethe problem. You may also be asked to share yourresults with a larger group or the class.• In a jigsaw activity, you are an active memberin two teams: your home team and your expertteam. Each member of the home team choosesor is assigned to a particular area of research.Each home team member then meets with anexpert team in which everyone is working on thesame area of research. In your expert team, youmay work together to come up with answers toquestions in your area of research. Once you haveaccomplished your task as a team, you return toyour home team, and it is your responsibility toteach what you have learned to the members ofyour home team. Each person on the home teamwill do the same thing.The guidelines of teamwork are importantwith the jigsaw, so try to keep them in mind asyou work with your expert and home teams.• A round table activity can be used to give yourgroup an opportunity to review what they know.Your group is given a pen, paper, and a questionor questions. Pass the pen and paper aroundand take turns writing one line of the solution.You can pass on your turn if you wish. Keepworking until the solution is complete. Check toensure that everyone understands the solution.Finally, working as a team, review the steps tothe solution.7.A.3. Investigations and ActivitiesThis kind of work is most effective when completedby small groups. Here are some suggestions foreffective group performance during investigationsand activities:• Make sure that each group member understandsand agrees to the role assigned to him or her.• Take turns doing the work during similar andrepeated activities.• Safety must come first. Be aware of where othergroup members are and what they are doing. Askyourself, what potential hazards are involved inthis activity? What are the safety procedures?NEL7. Study Skills 637

• Take responsibility for your own learning bymaking notes and contributing to any discussionsabout the activities. Make your own observationsand compare them with the observations of othergroup members (Figure 1).Figure 1 When you are working with one student or several,you can share and compare your results.7.A.4. Explore an IssueFollow these guidelines when you are conductingresearch with a group:• Divide the topic into several topics and assignone topic to each group member.• Keep records of the sources used by each groupmember.• Decide on a format for exchanging information(such as photocopies of notes, oral discussion,electronically).• When the time comes to make a decisionand take a position on an issue, allow for thecontributions of each group member. Makedecisions by compromise and consensus.• Communicating your position should also be agroup effort.7.A.5. Evaluating TeamworkAfter you have completed a task with your group,evaluate your team’s effectiveness using these criteria:strengths and weaknesses, opportunities, andchallenges.Reflect on your experience by asking yourself thefollowing questions:• What were the strengths of your teamwork?• What were the weaknesses of your teamwork?• What opportunities were provided by workingwith your group?• What challenges did you encounter as a memberof a group?7.B. Setting Goals andMonitoring ProgressThink back to your last school year. What classesdid you do well in? Why do you think you weresuccessful? In which classes did you have difficulty?Why do you think you had difficulty? What couldyou do differently this year to improve yourperformance? Use your answers to these questionsto reflect on your past experiences to make new andpositive changes. Things that you want to accomplishtoday, this week, and this year are all called goals.Learning to set goals and to make a plan to achievethem takes skill, patience, and practice.7.B.1. Setting GoalsAssess Your Strengths and WeaknessesThe process of setting goals starts with honestreflection. Maybe you have noticed that you do betteron projects than you do on tests and exams. You mayperform better when you are not pressured by time.Inattention in class and poor study habits may beweaknesses that result in poor performance.Realistic Goals That You Can MeasureDo not set yourself up to fail by setting goals that youcannot possibly achieve. Saying, “I will have the bestmark in the class at the end of the semester” may notbe realistic. Setting a goal to increase your test marksby 10 % this semester may be achievable, however.You will find it easier to reach your goals if you cantell whether you are getting closer to them. A goalto increase your test marks by 10 % this semester iseasy to measure. When you are thinking of settinggoals, remember the acronym SMART: Specific,Measurable, Attainable, Realistic, and Time-limited.638 Skills Handbook NEL

Share Your GoalsPeople whom you respect can often help you set andclarify goals. Someone who knows your strengths andweaknesses may be able to think of possibilities youmay not have considered. Sharing your goals witha trusted friend or adult will often provide neededsupport to help you reach your goals.Planning to Meet Your GoalsOnce you have made a list of realistic goals, createa plan to achieve them. A successful plan usuallyconsists of two parts: an action plan and target dates.The Action PlanFirst, make a list of the actions or behaviours thatmight help you reach your goals (Figure 2).Setting Target DatesSuppose you want to improve test results by 10 %by the end of the semester. How much time do youhave? How many tests are scheduled between nowand then? Work back from your target date at theend of the semester. Determine the dates of all thetests between now and the end of the semester.These dates will give you short-term targets that,if you hit them, will make it easier for you to reachyour overall target. Figure 3 shows an example ofa working schedule.Sept 30 Science book reportOct 15 Environmental mini-projectNov 26 Technology design projectDec 6 TestGoal: To increase my grades by 10 % by the end ofthe termPossible actions: assignments. Use it. Figure 2 One student’s goal and action plan to improve testresultsIf you have made an honest assessment of yourstrengths and weaknesses, then you know what youhave to do to improve. If you want to improve yourtest marks, you could try to work with others toprepare for tests. You could also use a weekly planneror reorganize your study area at home.Identify what is preventing you from achievingyour goal. Think of ways to overcome these obstacles.Ask friends for tips on the different ways that theymaintain good study habits and improve test results.Figure 3 Test datesOnce you complete your schedule in your planner,transfer it to a calendar in your study area. Refer toeither your planner or your calendar every day.7.B.2. Monitoring ProgressRemember to measure your progress along the way.It is always important to look at and monitor theresults of your tests and activities during the schoolyear rather than just at the end of it. You mightdecide, for example, to check your progress afterthe first test. Did these results meet your short-termtarget to improve test results by 10 % by the end ofthe semester? If you do not seem to be on track tomeet your goal, then you may need to change yourplan. For example, perhaps you need to study byyourself or with one friend rather than with a groupof friends.It is always possible to change your plan or evenadjust your goal. The most important thing is tokeep moving forward and to remain committedto improvement.NEL7. Study Skills 639

7.C. Good Study HabitsStudying takes many forms. Developing good studyskills can help you study and learn more successfully.Below are some tips to help you achieve better studyhabits.7.C.1. Your Study Space• Organize your work area. The place whereyou study should be tidy and organized. Placeall papers, books, magazines, and pictures inappropriate areas of your study area (e.g., keepbooks in a bookcase or crate and magazines ina stack on the floor). This will make it easier foryou to focus on your school work.• Maintain a quiet work area. Where possible,make sure that your work area is free fromdistractions—telephone, music, television, andother family members. If there are too manydistractions at home, you can usually find anappropriate space at the school or public library.Any quiet space, free from interruptions, can bea productive work area.• Make sure that you are comfortable in your workarea. If possible, personalize your work area.For example, make sure that the light is right foryour needs. Decide what works best for you andcreate a study area that provides a productiveand positive environment in which you feelcomfortable.• Be prepared—bring everything you need. It isimportant to have all the necessary materials andequipment that you will need when you begin tostudy. You can easily increase your productivityby gathering materials such as pens, pencils,notebooks, or textbooks in one place near yourcomputer or on your desk. Continually getting upto find something you need decreases your abilityto stay on task and be productive.7.C.2. Study Habits• Take notes. Take notes during class. Outsideclass, review the appropriate section of thetextbook. Read or view additional material onthe topic from other sources, such as newspapers,magazines, the Internet, and television. Ask afriend to share notes with you.• Use graphic organizers. You can use a varietyof graphic organizers to help you summarize aconcept or unit (page 642). They also help youmore easily connect different concepts.• Schedule your study time. Use a daily planner andtake it with you to class. Write any homeworkassignments, tests, or projects in it. Use it tocreate a daily “to do” list. This will help youcomplete work to hand in and avoid last-minutepanic. Also, jot down in your planner when,where, and with whom you plan to study forcertain topics.• Take study breaks. It is important to schedulebreaks into your study time. For example,you could decide to take a study break aftercompleting one or two items on your “to do” list.Taking breaks allows you to relax and to rechargeyour brain so that you can keep focused whenyou return to your assignments.640 Skills Handbook NEL

Literacy88.A. Reading StrategiesThe skills and strategies that you use to help youread depend on the type of material you are reading.Reading a science book is different from reading anovel. When you are reading a science book, you arereading for information. Here are some strategies tohelp you read for information.8.A.1. Before ReadingSkim the section you are going to read. Look at theillustrations, headings, and subheadings.• Preview. What is this section about? How is itorganized?• Make connections. What do I already know aboutthe topic? How is it connected to other topics Ialready know about?• Predict. What information will I find inthis section? Which parts provide the mostinformation?• Set a purpose. What questions do I have aboutthe topic?8.A.2. During ReadingPause and think as you read. Spend time on thephotographs, illustrations, tables, and graphs, as wellas on the words.• Check your understanding. What are the mainideas in this section? How would I state them inmy own words? What questions do I still have?Should I reread? Do I need to read more slowly,or can I read more quickly?• Determine the meanings of key science terms.Can I figure out the meanings of terms fromcontext clues in the words or illustrations? Do Iunderstand the definitions of terms in bold type?Is there something about the structure of a newterm that will help me remember its meaning?Which terms should I look up in the glossary?• Make inferences. What conclusions can I makefrom what I am reading? Can I make anyconclusions by “reading between the lines”?• Visualize. What mental pictures can I make tohelp me understand and remember what I amreading? Should I make a sketch?• Make connections. How is the information in thissection like information I already know?• Interpret visuals and graphics. What additionalinformation can I get from the photographs,illustrations, tables, or graphs?8.A.3. After ReadingMany of the strategies you use during reading canalso be used after reading. For example, this textbookprovides summaries and questions at the ends ofsections. These questions will help you check yourunderstanding and make connections to informationthat you have just read or to other parts in thetextbook.At the end of each chapter are a Key ConceptsSummary and a Vocabulary list, followed by aChapter Review and Chapter Self-Quiz.• Locate needed information. Where can Ifind the information I need to answer thequestions? Under what heading might I find theinformation? What terms in bold type should Ilook for? What details do I need to include in myanswers?• Synthesize. How can I organize the information?What graphic organizer could I use? Whatheadings or categories could I use?• React. What are my opinions about thisinformation? How does it, or might it, affect mylife or my community? Do other students agreewith my reactions? Why or why not?• Evaluate information. What do I know now thatI did not know before? Have any of my ideaschanged because of what I have read? Whatquestions do I still have?NEL8. Literacy 641

8.B. Graphic OrganizersDiagrams that are used to organize and displayideas visually are called graphic organizers. Graphicorganizers are especially useful in science andtechnology studies when you are trying to connecttogether different concepts, ideas, and data. Differentgraphic organizers have different purposes. They canbe used to• show processes• organize ideas and thinking• compare and contrast• show properties or characteristics• review words and terms• collaborate and share ideasTo Show ProcessesGraphic organizers can show the stages in a process(Figure 1).lungs(air containing oxygen,carbon dioxide,and other gases)water vapour(gas)evaporates intoPlant and Animal CellsBiology as a science is built on three simple found in but very important ideas. Thesethree ideas form the cell theory. The cell theory states that1. All living things are made up of one or more cells and their products.2. The cell is the simplest unit that can carry out all life processes.glacierspolar ice caps3. All cells come from other cells; they do not come fromsnownon-living matter.All living things are made up of cells, but these cells may be very simple orvery complex. The simplest organisms are archaea and bacteria. These simple,single-celled life forms are called prokaryotes (Figure 1(a)). The cells do nothave Mind a nucleus. maps More are complex similar cells can to exist concept as single-celled maps, organisms but they ormulticellular organisms. The cells of these organisms, known as eukaryotes,have a more complex internal organization, including a nucleus. Eukaryotesinclude all protists, fungi, animals, and plants, from the tiniest Amoeba to thelongest whale and the tallest tree (Figure 1(b) to (d)). The cells of eukaryotesare You much can larger use than a the tree cells diagram of prokaryotes: to tens show to thousands concepts of timeslarger. There are even some eukaryotes—beyond the scope of this unit—thatare made up of one huge cell with very many nuclei.prokaryotewithout anucleusfreezes intowater(liquid)ice(solid)ORGANISMwith anucleusis managed by monitoringconsumptiondo not have explanations for the connectionsbetween ideas.eukaryoteconservationFigure 2 Concept maps help show the relationships among ideas.that can be broken down into smaller categories(Figure 3).cell theory a theory that allare made up of one or morecells are the basic unit of lifecells come from pre-existingprokaryote a cell that doesa nucleus or other membranorganelleseukaryote a cell that contaiand other organelles, each sa thin membraneREADING TIPMaking ConnectionsWhen trying to make connwith a text, use prompts osuch as:O 2 CO 2(e.g., E.coli) )one cellsingle-celledorganismmany cellsmulticellularorganismcirculatorysystem(a)(e.g., Amoeba)animalplantO 2 CO 2tissues(cells requiring oxygenand producingcarbon dioxide)Figure 1 This organizer shows that oxygen and carbon dioxideare transported around the body.(b)(e.g., whale)(c)(e.g., pine tree)(d)Figure 3 Tree diagrams are very useful for classification.Cell StructureYour body is made up of many specialized organs that carry out all theprocesses can needed use to a live. fishbone In the same way, diagram a eukaryotic to cell organize also has specialized theimportant parts, called organelles, ideas under that carry the out major specific functions concepts necessary of for a topic life.you are studying (Figure 4).NELFigure 1 The relationshipprokaryotes and eukaryotbacterium (a) is a prokaryAmoeba (b), the whale (c)the pine tree (d) are all euorganelle a cell structure thspecifi c function for the cell2.1 Plant and AnimalTo Organize Ideas and ThinkingA concept map is a diagram showing the relationshipsbetween ideas (Figure 2). Words or picturesrepresenting the ideas are connected by arrows andwords or expressions that explain the connections.You can use a concept map to brainstorm what youalready know, to map your thinking, or to summarizewhat you have learned.Nature ofMatterClassifying MatterProperties of MatterFigure 4 A fishbone diagramChanges of StateParticle Theory642 Skills Handbook NEL

CSH-F49-SHOS10SB.aiWhat do we Know? What do we Want to find out? What did we Learn?Carbon dioxide is a greenhouse gas. Are there any other importantgreenhouse gases? If so, where dothey come from?Methane, water, and nitrous oxide are other commongreenhouse gases. Methane is released from decayingorganic matter and from the digestive tracts ofgrazing animals. Nitrous oxide is released inautomobile emissions.The greenhouse effect traps solarenergy in the atmosphere.If the energy of the Sun can get throughthe atmosphere and warm the Earth’ssurface, how is the energy trapped bygreenhouse gases?The atmosphere is transparent to light, allowing lightrays from the Sun to strike the Earth’s surface. Thisenergy is absorbed and then released as infraredwaves. Because the atmosphere is not transparent toinfrared waves, energy is trapped in the atmosphereand warms the Earth.Figure 5 A K-W-L chartYou can use a K-W-L chart to write down whatyou know (K), what you want (W) to find out, and,afterwards, what you have learned (L) (Figure 5).You can use a compare-and-contrast chartto show similarities and differences between twosubstances, actions, ideas, and so on (Figure 7).To Compare and ContrastYou can use a comparison matrix (a Should type of the table) last line to read “warms the Earth”?compare related concepts (Table 1).Table 1 Subatomic Particleslocation nucleus nucleusOntario Science 10 Skills Handbook0-17-635519-7FN You can use CSH-F48-SHOS10SBa Venn diagram to show similaritiesCO and differences CrowleArt (Figure 6). GroupDeborah acids Crowle basesPass2nd passApprovedNot Approved• pH 7• release OH – inwater• turn red litmusblueCSH-F48-SHOS10SB.aiSalt water 97.2 % of allwater on Earth containsdissolved salts(~3.5 %) more dense 1.03 g/cm 3 more buoyant objects floathigherHow are they similar? both liquids at room temperature found all over Earth look alikeHow are they different? distributionon Earth salinity density buoyancyFigure 7 A compare-and-contrast chartFresh water 2.8 % of allwater on Earth contains littledissolvedsalts less dense 1 g/cm 3 less buoyant objects floatlowerFigure 6 A Venn diagramNEL8. Literacy 643

To Show Properties or CharacteristicsYou can use a bubble map to show properties orcharacteristics (Figure 8).reproducegrowrepairthemselvesCharacteristicsof LivingThingsrequireenergyrespondto theenvironmentTo Collaborate and Share IdeasA placemat organizer gives students in a small groupa space to write down what they know about a certaintopic. Then group members discuss their answersand write in the middle section what they have incommon (Figure 10).Before:Before: Quietly write in your own sectionof this border, for a few minutes,Quietly write in your own sectionwhat you know about the topic.of this border, for a few minutes,what you know aboutSummarizethe topic.your group’s keyideas in this box.Summarize your group’s keyideas in this box.arecomposed ofcellsFigure 8 A bubble mapproducewasteTo Review Words and Termshave a lifespanYou can use a word wall to list, in no particular order,the key words and concepts for a topic (Figure 9).angle of incidencemiragefocal pointangle of refractionnormalluminescenceangle of reflectionvirtual imagemagnificationAfter:After: Bottled Water: Bottled water is Bottled Water: Not all plasticBottleda convenientWater:wayBottledto carrywaterwateris Bottledbottles getWater:recycled.Not all plasticatoconvenientoutdoor activities.way to carry water bottles get recycled.to outdoor activities.Risks to Health/Environment:RisksThe healthto Health/Environment:and environment risksTheof usinghealthbottledand environmentwater may notrisksbeBottled Water:ofworthusingthebottledconveniencewaterofmaythese Bottled Water:not beBottledSome ofWater:theworthproducts.the convenience of these BottledSome chemicalsWater:Someenergyofusedthetoproducts.Someused tochemicalsmakeenergyrecycleusedemptytowater bottles the plastic bottleusedhavetobeenmakefoundrecyclepollutesemptythe environment.water bottles thedissolvedplasticinbottlethe water.have been foundpollutes the environment. dissolved in the water.Figure 10 A placemat organizerinfraredelectromagnetic spectrumlightFigure 9 A word wallultravioletmediumCSH-F53-SHOS10SB.aiCSH-F53-SHOS10SB.aiOntario Science 10 Skills HandbookOntario 0-17-635519-7 Science 10 Skills Handbook0-17-635519-7FNCSH-F53-SHOS10SBFN COCSH-F53-SHOS10SBCrowleArt GroupCOCrowleArt Deborah Crowle GroupPassCSH-F52-SHOS10SB.aiDeborah 2nd pass CrowlePass Approved 2nd passApproved Not Approved644 Skills HandbookNot ApprovedNEL

Latin and Greek Root Words9Prefix Latin or Greek Meaning Exampleant- Greek opposing antacid; Antarcticanthrop- Greek related to people anthropogenicaqu- Latin water aqueous solution; aquatic ecosystembio- Greek life biology; biospherecardio- Greek related to the heart cardiologyco- Latin with or together covalent bond; converging lensdi- Greek two diatomic moleculeepi- Greek upon or over epidermishal- Greek sea salt halogen; halophilehemo- (haemo-) Greek related to blood hemoglobinhydro- Greek related to water hydrosphere; hydroelectrichyper- Greek more or excessively hyperopia; hyperactiveinfra- Latin below or lower infrared radiationinter- Latin between interphase; interglacial periodlitho- Greek rock lithospherelum- Latin related to light luminousmeta- Greek beyond metamorphosismicro- Greek small micro-organismmono- Greek one carbon monoxideperi- Greek around peripheral nervous system; peridermpoly- Greek many polyatomic ionpro- Greek and Latin before prophase; propagatepseudo- Greek false pseudoscienceretro- Latin turned back retro-reflector; retrogradesal- Latin related to salt saline solutiontherm- Greek heat thermometer; thermoclinetrans- Latin through or across transparent; transistorultra- Latin above or beyond ultraviolet radiationxeno- Greek foreign or other xenotransplantationSuffix Latin or Greek Meaning Example-gen Greek to make or generate carcinogen; halogen-meter Greek measure conductivity meter-ology Greek study of geology-stasis Greek location metastasisNEL9. Latin and Greek Root Words 645

10Periodic Table11 1+1–31Hhydrogen1.011+422+Nelson Science Perspectivesatomic number26Key3+2+most common ion chargeother ion charge2Lilithium6.9411 1+ 12Beberyllium9.012+symbol of element(solids in black,gases in red,liquids in blue)Feiron55.85name of element3NasodiumMgmagnesium22.99 24.31atomic mass (u)—based on C-123 4 5 6 7 81+2+19 20 21 3+ 22 4+ 23 5+ 243+252+263+4+2+4+3+2+2792+3+4567Kpotassium37 1+ 38Rbrubidium55 1+ 56CacalciumSrstrontiumScscandium39 3+ 40Yyttrium72TititaniumZrzirconiumVvanadiumCrchromiumMnmanganese39.10 40.08 44.96 47.87 50.94 52.00 54.94 55.8541 5+ 42 6+ 43 7+ 44NbniobiumMomolybdenumTctechnetium73 5+ 74 6+ 75 7+ 7687 1+ 88 2+ 893+ 104 105 106 107 108FrfranciumRaradium2+2+4+4+RfrutherfordiumDbdubnium3+SgseaborgiumBhbohriumFeironRurutheniumHshassium(223) (226) (227) (261) (262) (266) (264) (277)3+4+4+4577109Cocobalt58.93Rhrhodium85.47 87.62 88.91 91.22 92.91 95.94 (98) 101.07 102.9157Acactinium3+2+Cs Ba La Hf Ta W Re Os Ircesium barium lanthanum hafnium tantalum tungsten rhenium osmium iridium132.91 137.33 138.91 178.49 180.95 183.84 186.21 190.23 192.222+Mtmeitnerium(268)3+4+AlkalimetalsAlkalineearth metals58 3+ 59 3+ 603+613+623+2+MetalsMetalloidsNonmetalsHydrogen690Ce Pr Ndcerium praseodymium neodymium4+91 5+ 924+6+4+Pmpromethium140.12 140.91 144.24 (145)935+94Smsamarium150.364+6+7ThthoriumPaprotactiniumUuranium232.04 231.04 238.03Npneptunium(237)Puplutonium(244)646 Skills Handbook NEL

Periodic Table of the ElementsMeasured values aresubject to change asexperimental techniquesimprove. Atomic molarmass values in this tableare based on IUPAC Website values (2005).513 14 15 16 17Bboron—613 3+ 14Ccarbon——7Nnitrogen3–8Ooxygen2–15 3– 16 2– 179Ffluorine1–1–2101818Hehelium4.00Neneon10.81 12.01 14.01 16.00 19.00 20.18———1210 11 12Alaluminium282+292+302+313+323+1+Sisilicon26.98 28.094+PphosphorusSsulfurClchlorine33 3– 34 2– 351– 36Arargon30.97 32.07 35.45 39.95—346 2+ 47 1+ 4878NinickelPdpalladium3+4+2+CucopperAgsilver79 3+ 802+ 81 1+ 82 2+ 83 3+ 84 2+ 851– 86110 111 112ZnzincCdcadmiumGagalliumGegermanium58.69 63.55 65.41 69.72 72.641+2+1+AsarsenicSeseleniumBrbromine49 3+ 50 4+ 51 3+ 52 2– 53 1– 54Inindium3+Sntin2+4+Sbantimony5+5+TetelluriumIiodine114 115 116 117 1184+Krkrypton74.92 78.96 79.90 83.80Xexenon106.42 107.87 112.41 114.82 118.71 121.76 127.60 126.90 131.29PtplatinumAugoldHgmercuryTlthallium113PbleadBibismuthPopoloniumAtastatineRnradon195.08 196.97 200.59 204.38 207.2 208.98 (209) (210) (222)——456DsdarmstadtiumRgroentgeniumUubununbiumUuqununquadium(281) (272) (285) (284) (289)63 3+ 64 3+ 65 3+ 66EueuropiumGdgadoliniumTbterbium95 3+ 963+ 97 3+ 98Amamericium2+4+CmcuriumBkberkelium4+UutununtriumDydysprosiumCfcalifornium3+3+67 3+683+693+ 70HoholmiumErerbiumTmthulium99 3+ 100 3+ 101 2+ 102EseinsteiniumUupununpentium(288)FmfermiumUuhununhexium(291)3+MdmendeleviumUusununseptiumHalogensYbytterbium151.96 157.25 158.93 162.50 164.93 167.26 168.93 173.04Nonobelium(243) (247) (247) (251) (252) (257) (258) (259)3+2+2+3+Uuoununoctium71103(294)Noble gasesLulutetium174.972+3+Lrlawrencium(262)767NEL10. Periodic Table 647

appendix bWhat IsScience?648 What Is Science?NEL

the nature of scienceCharacteristics of ScienceScience is both a collection of what we know and howwe know about the world around us—both a body ofknowledge and a process for acquiring knowledge.• Science starts from observations that lead toquestions. The natural world is full of fascinatingphenomena that raise questions in the curiousmind. These questions form the basis of scientificinvestigation.• Scientific knowledge can come from observation.Observations that are made and recorded ina structured, organized fashion can provideevidence that leads to knowledge andunderstanding. Empirical knowledge includesknowledge gained in the process of scientificinquiry, as well as observations and knowledgegained from Aboriginal peoples, as part of theirtraditional ecological knowledge and wisdom(TEKW).• Science is done differently in different cultures. Themethods used to conduct scientific investigationsmay vary depending on social and culturaltraditions and practices. However, the purpose ofscientific inquiry remains the same: to understandand explain the natural world.• Scientific knowledge is tentative but reliable.Scientific hypotheses are ideas to be tested.Repeated testing that produces consistent resultscan lead to laws and theories that help to describeand explain the natural world. Current laws andtheories are reliable because of extensive testing,but they can change if new evidence suggests thata change is necessary. In science, a conclusion isnever regarded as final.• Science is progressive. Scientific knowledge buildson existing knowledge. Our understanding ofthe natural world grows as new knowledge isacquired and as new technologies enable furtherscientific investigation.• Science is repeatable, self-correcting, and not basedon authority. A hypothesis should be tested insuch a way that the same test can be repeatedby different people. This way, inconsistenciescan be identified and theories can be updatedto explain new observations. Modern sciencedoes not accept the proclamations of famousindividuals or people in positions of political orsocial authority unless they can provide credibleevidence to support their claims.Misconceptions about ScienceMany people misunderstand what science is and whatit can do. Some of the most common misconceptionsare briefly described here.Misconception #1: All scientists follow ASINGLE scientific method.Many people think that there is one “scientificmethod” that all scientists follow to conduct research.This method is usually described as a series of steps:1. A scientist asks a testable question and developsa hypothesis.2. The scientist designs and carries out an experiment,makes observations, and analyzes them.3. The scientist draws a conclusion based on theevidence and compares the conclusion with thehypothesis to determine whether the evidencesupports the hypothesis.NEL The Nature of Science 649

This is a valid research method, but differentscientists use different skills, technologies, andmethods. There are similarities, however. Sciencefollows procedures that generally lead to a logicalconclusion, which addresses the goal of theinvestigation. However, there is no single scientificmethod that all scientists follow, step by step. Theterm “scientific method” refers to the general typesof mental and physical activities that scientists use tocreate, refine, extend, and apply knowledge.Misconception #2: Science always involvesexperimentation.Experimentation is not the only approach toconducting scientific investigations, nor is it the onlyway of building scientific knowledge. Many scientificinvestigations are not experiments. Some sciences,such as astronomy and environmental science, donot lend themselves to experimentation becausescientists cannot control the conditions in whicha phenomenon occurs. Other types of scientificinvestigations are equally valid for producingvaluable scientific knowledge. For example, most ofour understanding about climate change is basedon extensive observations and analysis of naturallyoccurring phenomena.Misconception #3: Science investigationsprovide proof.Although scientific investigations can result inscientific knowledge, they cannot provide proof.Empirical evidence can support or validate a lawor theory but can never prove a law or theory to betrue. Science can only show that an idea is false ordisproven. Consider the law of gravity. The evidencecollected worldwide leads scientists to concludethat objects denser than air always fall downward,or toward Earth’s centre. An observation in whichan object denser than air falls upward (away fromEarth’s centre) would seriously challenge our currentunderstanding of the law of gravity.Scientific laws are reliable. Because they arebased on such vast numbers of observations, itis very unlikely that evidence will be found toprove them false. In fact, scientific laws are seldomproven false. The law of gravity and other scientificlaws are probably as close to scientific “truth” aswe may ever come.Misconception #4: Science is not verysuccessful.Science is often criticized because of what it has notdone—for example, it has not found a cure for canceror the common cold. However, when we consider theoutstanding achievements of science, we can see that ithas been very successful in helping us understand thestructure of the natural world and how it functions.For example, we are confident in our knowledgethat matter is made of non-visible atoms, that livingthings are made of cells that pass on information inthe genetic material DNA, and that the continents areslowly moving across the surface of Earth.Scientific and technological knowledge has allowedus to land on the Moon, communicate at the speedof light, and perform open-heart surgery. Recentadvances in the diagnosis and treatment of cancerare possible because scientists are learning more andmore about what causes cancer and how differenttypes of cancers behave. A cure for all cancers hasnot yet been found, but the knowledge that is beinggathered may one day provide this cure. Science isnot perfect, but it is the most reliable way we have toexplore and make sense of the natural world.Misconception #5: Science can provide theanswers to all questions.Although scientific inquiry is a highly efficientway to learn about the structures and functions ofthe natural world, it cannot answer moral, ethical,and social questions. Should we allow mining inenvironmentally sensitive areas? Which of 10 patientsshould receive a donor kidney? Questions suchas these cannot be answered by science. Scientificknowledge can, however, provide information to helpindividuals and groups make important decisions onsuch issues.650 What Is Science? NEL

What Is Not science?It is important to understand what science is about.It is also important to recognize what is not science.Information can be presented, intentionally orunintentionally, as science even though it is notreally science. Examples abound on television, inmagazines, and on the Internet.PseudosciencePseudoscience (pseudo means “false”) is the practiceof presenting claims so that they appear scientific,even though they have not been scientificallytested and are not supported by sound scientificevidence. For example, the alternative medicalpractice of magnetic healing (Figure 1) relies onthe scientific concept of magnetic fields to give itcredibility. Supporters of magnetic healing claim thatmagnetic fields promote the healing of bones and theimprovement of blood circulation. These supporters,including some apparently credible scientists,provide testimonials about the healing effects ofmagnetic therapy. However, the little scientifictesting done on magnetic healing has found noevidence of healing effects.beliefs, and possibly a desire to be accepted by otherscientists, investigators may design and conductexperiments that are guaranteed to obtain results thatsupport their position. Valid evidence may also beincorrectly analyzed or interpreted.Hoaxes and FraudsHoaxes and frauds are intentional attempts to misleadpeople with false claims or with information that ismisrepresented. Scientific hoaxes and frauds preyupon people’s lack of scientific knowledge.Hoaxes may be carried out as a joke, but theymay also be motivated by greed, desire for fame,or pressure to announce a significant scientificdiscovery. Most hoaxes are pranks, and the only harmdone is the embarrassment of falling for the trick.Would you fall for a hoax? How can you guardagainst being deceived? One way is to look closelyat the claim and compare it with what you alreadyknow. Figure 2 is a touched-up photo of a tsunamiabout to crash over a city. The wave appears to behigher than the 20-storey building. An average storeyis 3 m, so this wave would be higher than 60 m. Thisis unlikely since tsunami waves generally range inheight from 1 m to 20 m.Figure 1 The magnetic field in most magnetic therapy devices isnot strong enough to penetrate the skin.Faulty ScienceFaulty science results when scientists do not followthe established standards and practices that sciencerequires. Faulty science often results when scientificmethods are affected by bias. Bias occurs when ascientist allows emotions or personal values to affectthe analysis of data. In general, scientists strive to beobjective and unbiased when conducting scientificinvestigations. However, because they are human, theinvestigators may believe something to be true beforethey have evidence to support it. Because of theirFigure 2 Is this tsunami real?NEL The Nature of Science 651

Myths and Urban LegendsThere are many interesting stories or claims that havecirculated so widely, and for so long, that they aregenerally accepted as true. Such stories, referred to asurban legends, are often presented as being scientific,and many people never question their validity. Theproblem with urban legends is that they are usuallyfar-fetched but somewhat believable at the sametime. Although most of these stories are false, someare actually true. For others, it might be impossibleto determine whether they are true or false. Can youidentify those that are true?• A penny placed on train tracks will derail a train.• Sharks do not get cancer, so eating shark cartilagecan prevent cancer in humans.• The average person accidentally swallows eightspiders per year.• Water that is boiled in a microwave can explode.• Lemmings jump off cliffs to commit suicide.• Hair grows back thicker and longer after it isshaved.• Swimming after eating may result in a crampthat causes a person to drown.Science in MarketingHow many advertisements do you see in an averageday? Ten? One hundred? Have you ever thoughtabout why companies advertise and whetheradvertising works? What strategies do advertisersuse to catch our attention and to convince us tobuy their products?A common advertising strategy is to claim that aproduct was scientifically developed. Examplesinclude “scientifically formulated” facial cleansersor “clinically proven” weight loss supplements.Advertisers believe that the positive public image ofscience will convince consumers that a product iseffective, of good quality, or safe. Advertisements mayfeature images of researchers in white lab coats in alaboratory, or wording that conjures up this image inpeople’s minds. The problem with this type of claim isthat consumers are expected to believe that crediblescientific investigations were used to develop andtest the product.Advertisers sometimes use scientific language tomake the product seem authentic. For example, acommon advertising phrase in today’s environmentallysensitive world is “chemical free,” as in “chemicalfreecleaning products.” Although this may soundconvincing at first, after a little thought it is obviousthat no product can be chemical free. All products aremade of matter, and all matter is made of chemicals.So, the “chemical free” claim is meaningless.TRy ThisSkills:Analyzing, EvaluatingSCIENTIFIC OR NON-SCIENTIFIC?To be considered scientific, evidence or information must beboth falsifiable and reproducible. In other words, we must beable to conduct a fair test to determine whether the informationis false, and we must be able to reproduce the research toproduce the same information. Using these two criteria and theinformation you acquired about the nature of science and aboutwhat is not science, analyze each of the following statementsand decide whether it is scientific or non-scientific. Explainyour answer. (Remember, the aim is not to decide whetherthese statements are true or false but rather whether they arescientific or non-scientific.)(a) The pyramids were built by extraterrestrial beings.(b) Wearing a magnetic bracelet will improve your golf game.(c) Ancient Egyptian kings and queens were mummified so thattheir soul could go to the afterlife.(d) The speed of an object falling due to gravity will increase by9.8 m/s each second.(e) Adding fertilizer to a lawn will make the grass greener.(f) There is a creator who created and controls the universe.(g) The more you study, the lower your test scores will be.(h) There is life elsewhere in the universe.(i) If you turn a potted plant upside down, the plant stem willcontinue to grow toward the ground.(j) Plants are aware of their surroundings.(k) Your horoscope can be used to predict your future.652 What Is Science?NEL

Although many products and foods are indeedscientifically formulated and clinically proven,it is impossible to judge from the advertisementwhether the quality of the scientific investigationmet acceptable standards. In many cases, a thoroughinvestigation of the product reveals that there is noaccepted scientific basis for the claims that are made.Being SkepticalSkepticism is an important part of being scientificallyliterate. Being skeptical does not mean that youdismiss all claims that you encounter; it means thatyou must question all claims, including your ownbeliefs and conclusions, until sufficient evidence isavailable for you to accept or reject the claims. Askeptical person must be open-minded and be willingto change his or her understanding about naturewhen faced with sound scientific evidence and logicalarguments.How can you tell what is scientific?You encounter bizarre and outrageous claims dailyabout science-related matters. You need a way todecide what is true and what is pseudoscientific,faulty science, or an urban legend. The methods ofscience combined with ordinary critical thinkingwill help you make such decisions. You should askyourself a few questions when faced with a claim:• Does the information source (person and/ororganization) making the claim have appropriatecredentials or qualifications?• Is there evidence of bias or a conflict of interest?• Were valid and appropriate scientific methodsused to produce the information?• Were the results reviewed by other scientists?Were the other scientists able to replicate theresearch and get the same results?• Do the conclusions make sense? Are theconclusions supported by evidence?• Does the phenomenon or product work asclaimed?As you encounter the topics and issues in thistextbook, and claims to scientific knowledge in youreveryday life, analyze the available informationto determine what is and what is not scientific.Knowing that people will provide arguments tosupport their opinion or position, think criticallyabout the claims of those representing differentperspectives. Above all, use empirical evidence,ordinary common sense, and your personal valuesto help you accept or reject an argument and tomake and defend your own position on an issue.Ethical Behaviour in ScienceEthics is the study of what is right and wrong andhow this affects the way we behave as individuals oras a group. Ethics provides us with a guide to whichbehaviours are acceptable and which are unacceptable.There are acceptable and unacceptable behavioursin science. A scientist should act in an unbiasedmanner. We know, however, that scientists aresometimes affected by their emotions and their values.There is a set of general rules, or guiding principles,that all scientists should follow when conductingscientific research.• The principle of scientific honesty: Do not commitscientific fraud. In other words, do not fabricate,trim, destroy, or misrepresent valid data. Reportall results accurately.• The principle of carefulness: Make every effort toavoid careless errors or sloppiness in all aspectsof scientific work. Think about the potentialconsequences of careless errors.• The principle of intellectual freedom: Do not beafraid to pursue new ideas and criticize all ideas,old and new. Feel free to conduct research in anarea that interests you.• The principle of openness: Share data, results,methods, theories, equipment, and so on. Allowothers to see your work and be open to criticismand suggestions.• The principle of credit: Do not claim other people’swork as your own. Give credit where it is due.• The principle of public responsibility: Report theresults of scientific research to the public if it hasimportant implications for society, but only afterthe results has been validated and verified by otherscientists.NEL The Nature of Science 653

Science, Technology, Society,and the Environment (STSE)Science and technology are very different activities,but we often hear about them together. This isbecause they are closely related and often go handin hand. Scientists rely on technologies to furthertheir research, and technologists rely on scientiststo understand the scientific basis of technologicaldevelopments.A Partnership: Science andTechnologyScientific research produces knowledge, orunderstanding of natural phenomena. Technologistsand engineers look for ways to apply this knowledgein the development of practical products andprocesses. For example, scientists want to know howdifferent materials affect the transmission of X-rays(Figure 3). Technologists and engineers focus onusing that knowledge to explore inside solid objects,including the human body. Scientists use technologiesin their research. Engineers and technologists may usescientific knowledge and principles when designingand developing new technologies.Figure 3 Knowing that X-rays do not pass through dense materialsuch as bones, technologists designed machines that use X-rays andfilm or a computer to provide an internal view of the human body.In some cases, technological inventions andinnovations occur before the scientific principles areknown. For example, practitioners of early traditionalmedicine used specific plants to treat specific conditionslong before modern medical professionals understoodhow the chemicals in these plants affected human bodyfunctions. In other cases, scientific discoveries are madebecause of technological inventions. For example, theinvention of glass lenses led to the development of earlymicroscopes (Figure 4), which allowed scientists to seemicro-organisms that cause diseases.DID YOU KNOW?Discovery of BacteriaAnton van Leeuwenhoek (1632–1723), a Dutch scientist with noformal education, designed many simple microscopes, which enabledhim to discover bacteria. He described them as “incredibly small, nayso small, in my sight, that I judged that even if 100 of these very weeanimals lay stretched out one against another, they could not reach tothe length of a grain of coarse sand.”go to nelson scienceFigure 4 The development ofthe light microscope followedthe understanding of thestructure and behaviour ofglass lenses.The invention of glass lenses also led tothe development of telescopes, which allowedastronomers to observe our solar system and theuniverse. The telescope, in turn, led to more accurateastronomical observations and measurements, whichcontributed to the change from an Earth-centredscientific model of the universe to a Sun-centredmodel. Many other technologies, including thethermometer and the computer, have greatly helpedthe advancement of science. You can see how scienceand technology often support each other.Sometimes, technological inventions followscientific discoveries (Table 1 on page 655). Forexample, the television was invented after scientistshad created theories to explain the structure of theatom and understood electrons, current electricity,and electromagnetism. The relationship betweenscience and technology is mutually beneficial;scientific discoveries lead to technological advances,which lead to further scientific discoveries, and so on.654 What Is Science? NEL

You may have heard in the media that somedisease-causing bacteria are becoming resistantto antibiotics. Viruses are another form of microorganism(Figure 5). Scientists recently discoveredmore about how viruses make, package, and insertgenetic information into living cells. With thisknowledge, technologists can design a virus that willseek out and kill disease-causing bacteria.Figure 5 The Influenza-A virusTable 1 Examples of the Science–Technology RelationshipScience Technology ExampleBiologists learn how the heartfunctions.Engineers and technologists designreplacement valves and artificialhearts.Replacement heart valveChemists learn about the structureof materials.Engineers and technologists designuseful products, using materials withsuitable properties.New materials such asKevlar or Zylon, used inprotective gearEarth scientists observe how radiowaves are reflected off differentsurfaces, such as snow and rock.Technologists use satellite radarimaging to view Earth from space.Satellite image ofa coastlinePhysicists discover how light behaveswhen it passes through or reflects offdifferent materials.Technologists design lenses andmirrors for telescopes, microscopes,and other optical devices.Optical telescopeNEL Science, Technology, Society, and the Environment (STSE) 655

Science, Technology,and SocietyYou do not have to look far to find evidence of theimpact of science and technology on society. Manyimportant discoveries and inventions have occurredwithin the last century—vaccines, antibiotics, organtransplants, reproductive technologies, geneticengineering, pesticides, atomic weapons, computers,lasers, plastics, televisions, communication satellites,and the Internet. The homes we live in, the food weeat, the vehicles we drive, and the electronic gadgetswe use are all products of scientific and technologicalachievement (Figure 6).(a)Figure 6 Examples of science and technology in our daily lives:(a) WiiFit (b) hybrid car engine.There are obvious influences of science andtechnology on society. But science and technologyare influenced by society as well. The values andpriorities of society at a particular time can influencethe direction and progress of developments in bothscience and technology. For example, our desire toreduce greenhouse gas emissions is encouraging therapid development of vehicles and machinery thatuse alternative fuels.Scientific and technological research is veryexpensive. Research facilities employ highly paid andhighly skilled professionals. The facilities consumelarge amounts of energy and require expensive andsophisticated tools and equipment. Funding forresearch comes from both private and public sources.It may be a long time between the beginning ofresearch and development and the release of a newproduct or process.Basic ResearchBasic research helps people learn more about howthe natural world works and is essentially the sameas scientific investigation. Basic research—in areassuch as biochemistry, particle physics, astronomy, andgeology—usually receives funding from governmentgrant agencies.(b)This type of research often produces knowledgethat engineers and technologists can use to developpractical solutions to everyday problems. Thepriorities of government, representing the prioritiesof the public, determine which areas of research arefunded.Applied ResearchApplied research is primarily focused ondeveloping new and better solutions to practicalproblems. Applied research can be equated withthe development of technology. Research into thedevelopment of technology—such as new cosmetics,sports equipment, telephones, automobiles, computersoftware and hardware, medical equipment, andpharmaceuticals—is usually carried out by privatelyowned companies. The marketplace, or the publicdemand for new products, will obviously influencewhich areas of research private companies fund. Ifmarket analysis shows that there is a demand forbetter cellphones or more fuel-efficient cars, researchand development in these areas will be supported.There are risks and benefits associated with manyscientific and technological developments. Althoughmost technologies are developed with the intentionof solving problems, there are often unintendedconsequences associated with their use. Socialnetworking sites, and other Internet technologies, cangreatly facilitate communication; however, the sametechnology is also used to commit crimes.It is difficult, if not impossible, to foresee allof the consequences of technologies. Often, newapplications of scientific and technological knowledgeare found long after the knowledge was first acquired.An important question remains up for debate. Whois responsible for the negative impacts of scienceand technology on society: scientists, science andtechnology, or human use of science and technology?Science, Technology, andthe EnvironmentSince the beginning of the Industrial Revolutionin the late 1700s, the industrialized world has usednatural resources at an increasing rate. With the useof resources, the development of technology, and thehuman population all increasing, we are producingwaste faster than ever.656 What Is Science? NEL

TRy ThisSkills:Analyzing, Evaluating, Communicatingdistinguishing between basic and applied researchScience and technology are so intertwined and dependent on eachother that it is sometimes difficult to distinguish between the twoor to determine where one ends and the other begins.1. In a small group, consider each of the following descriptions.Discuss each description and decide whether it refers tobasic research, applied research, or both. Explain your choicefor each statement.• Researchers have designed a virus that will carry geneticinformation to a specific type of bacterial cell, causing thebacterium to self-destruct.• Eliminating the oxygen from a package containing freshproduce extends its refrigerator life.• NASA astronauts observed that crystals grown in theInternational Space Station are perfectly formed.• A group of researchers has discovered how a virus deliversDNA to a living cell.• Certain materials, known as superconductors, can conductelectrical energy very efficiently, with practically no loss ofenergy as heat.• Government researchers are trying to determine what causessome maple trees to lose all of their leaves in midsummer.• Researchers have designed a flexible lens that changesshape in response to electrical stimuli.• Superconductor materials are used in new computers.• A car manufacturer’s research lab has built a battery forits electric car that can store 50 % more energy than otherbatteries.• Chemical researchers have found a new chemical processthat absorbs carbon dioxide.Many of the by-products of human industry andtechnology become pollutants. For example, thereare hundreds of millions of discarded cellphones inNorth America, most of which end up in landfills(Figure 7).Figure 8 illustrates how technology can transformthe energy of the Sun into electrical energy. Thistechnology is generally more environmentallyfriendly than the use of fossil fuels. Researchers inthe auto industry are busy developing vehicles thatuse alternative sources of energy and are more fuelefficient. The intention is that these vehicles will haveless of an impact on the environment.Figure 7 Cellphones contain hazardous substances such as lead,mercury, and arsenic. These metals can leach into groundwater ifthey are dumped into landfills.The impact of science and technology on theenvironment is not always negative. There are manypositive effects of science and technology. Newknowledge improves our understanding of the naturalworld, and new technologies allow us to live with theenvironment in a more sustainable way.(a)Figure 8 (a) Small solar panels can charge your cellphone.(b) Large panels can heat water or power your home.The relationships among science, technology,society, and the environment are complex. To makewise personal decisions and to act as responsiblecitizens we must think carefully about the influencesof each of these elements on the other. We eachhave a responsibility to ourselves, to society, andto future generations to become scientifically andtechnologically literate.(b)NEL Science, Technology, Society, and the Environment (STSE) 657

COMPONENTSISBNStudent Text 978-0-17-635528-9Student eBook 978-0-17-635529-6Teacher’s Resource 978-0-17-635530-2ExamView ® Test Bank 978-0-17-635533-3Interactive Toolkit DVD 978-0-17-635532-6GRADE 10 AUTHOR TEAMChristine Adam-CarrMartin GabberChristy HayhoeDoug HayhoeKatharine HayhoeMilan SanaderSENIOR PROGRAM CONSULTANTMaurice DiGiuseppePROGRAM CONSULTANTSDoug FraserMartin GabberDoug HayhoeJeff MajorDigital sample material for Science Perspectives 10 is available online.For more information about the program visit:www.nelson.com/scienceperspectivesTo order the finalStudent Text, please use:ISBN 978-0-17-635528-9ISBN-13 : 978-0-17-611660-6ISBN-10 : 0-17-611660-5www.nelson.com9780176 116606