Chapter 4.pdf

More documents

Recommendations

Info

$Math Alignment Project - Grand Erie District School First Class Web ...$

Science in My FUTURE Lost Wax — Found Metals The Art of Chemistry Figure 4.34 The final product Figure 4.33 Foundry artisans working with hot liquid metal Imagine sculpting a beautiful object or statue in clay and then transforming it into a single solid piece of metal. This is the job of a foundry artisan. A foundry artisan is a master of both the art and science of manipulating matter. A foundry is a place where metals such as gold and iron are fashioned into specialized parts. The metal is first melted until it becomes a liquid and then poured into a mould where it can harden and take on a new shape. An artisan adds creativity to the process, often making one-of-a-kind pieces of art. It may take an artist a week or a month to make a clay sculpture. When it is ready, the sculpture is brought to a foundry, where the work is completed. The clay sculpture is covered with silicone rubber to form a mould. The mould is a “negative” version of the clay sculpture. Hot wax is poured into the mould to coat the inside. This step is repeated until a “positive” version of the clay sculpture has been created. This looks just like the original clay sculpture. A second negative of the sculpture is made by coating the wax with a ceramic material, which is a solid that can withstand the heat of molten metal without breaking. Melting away the wax creates an empty vessel into which molten metal can be poured. One major step remains before the cast metal piece of art is complete. A hot furnace is used to heat aluminum, silver, iron, or gold until it melts. The metal is then poured into the empty mould, where it takes on the shape of the original clay sculpture (Figure 4.33). After allowing the mould to cool slowly, it is removed and the metal piece is sanded and polished to add the finishing touches. The cast metal art is now ready for sale or shipping to the museum or person who commissioned it (Figure 4.34). The work of a foundry artisan takes a combination of skills and talents. Being able to visualize the finished product from the start is important. A foundry artisan is creative, pays attention to detail, and has the self-discipline to meet deadlines. Also, an artisan must know how to work safely in the foundry. Most artisans apprentice with an expert in order to learn the specific skills they need for foundry work. Many have been to art college or studied the arts in university. It is common for artisans to be self-employed, and so basic business training can be helpful. Questions 1. The process of casting a piece of artwork in metal involves making several positive and negative versions of the final cast object. Sketch a flow chart that identifies these steps. 2. ScienceSource Research where you can take courses in jewellery casting or foundry art. Matter has physical and chemical properties. 163
4 CHAPTER REVIEW ACHIEVEMENT CHART CATEGORIES k Knowledge and understanding t Thinking and investigation c Communication a Application Key Concept Review 1. What is the main difference between a pure substance and a mixture Name an example of each. k 2. What is a chemical change 3. In the following diagram, what change of state does each letter indicate k k 8. What are two physical changes that cooling a hot substance may result in k 9. For each example, identify whether the property described is chemical or physical. Justify your answer in each case. c (a) Bronze metal has a shiny lustre. (b) When silver nitrate is added to calcium chloride, a cloudy solid (precipitate) appears. (c) Mercury is liquid at room temperature. (a) Connect Your Understanding solid (b) (d) liquid (c) (e) gas 10. Identify the processes shown in the following photographs as chemical changes or physical changes. Justify your answers. (a) t (f) 4. Low-density polyethylene is a plastic that can be stretched somewhat without breaking it. Why is this property useful for disposable shopping bags k 5. Explain the difference between cohesion and adhesion, using an example. c (b) 6. Explain why particles of water in the air can form frost on a cold window. k 7. Name a physical property that is: (a) shared by gold, copper, and iron (b) shared by gold and copper but not iron (c) shared by diamond and glass (d) not shared by diamond and glass k (c) Question 10 164 UNIT B Atoms, Elements, and Compounds
Page 1 and 2: UNIT B Atoms, Elements, and Compoun
Page 3 and 4: Exploring We use plastic bags to ca
Page 5 and 6: 4 Matter has physical and chemical
Page 7 and 8: 4.1 Investigating Matter Here is a
Page 9 and 10: Suggested Activity • B4 Quick Lab
Page 11 and 12: Particles and Heat In ice, the part
Page 13 and 14: Figure 4.9 A chocolate chip cookie
Page 15 and 16: DI Key Activity B3 Inquiry Activity
Page 17 and 18: B4 Quick Lab Foam in a Cup You can
Page 19 and 20: 4.2 Physical and Chemical Propertie
Page 21 and 22: Figure 4.18 Water sticks to itself,
Page 23 and 24: Suggested Activities • B7 Inquiry
Page 25 and 26: Controlling Changes in Matter to Me
Page 27 and 28: B7 Inquiry Activity Skills Referenc
Page 29 and 30: B8 Inquiry Activity Investigating P
Page 31 and 32: B9 Design a Lab Properties of Commo
Page 33: Investigating CAREERS in Science Gr

Chapter 4.pdf

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?