Year 7 Science Half Yearly Examination Revision Sheet Section 2 ...

Year 7 Science
Half Yearly Examination Revision Sheet ­ Section 2: Solids, Liquids and Gases and Mixtures
and Their Separation
You need to revise the following objectives in preparation for this section of the examination
Solids, Liquids and Gases
1. Describe the behaviour of matter in terms of particles that are continuously moving and
interacting.
2. Identify the three main states of matter.
3. Describe how the particle model explains the different states of matter.
4. List the properties of solids, liquids and gases.
5. Relate the properties of solids, liquids and gases to the particle model of matter.
6. Define the term "change in state".
7. Describe the physical changes that take place during evaporation, condensation, boiling,
melting, freezing and sublimation.
8. Relate changes of state to the motion of particles as energy is removed or added.
9. Relate energy transfers in evaporation, condensation, boiling, melting, freezing and
sublimation to the particle model.
10. Define the term "density" and explain density in terms of the particle model.
11. Calculate the density of solids and liquids.
Mixtures and their Separation
1. Describe how a solution is formed.
2. Define the terms "solute" and "solvent".
3. Identify solutes and solvents in common solutions.
4. Describe the difference between a "soluble" and an "insoluble" substance.
5. Define the terms "concentrated", "dilute" and "saturated" as they apply to solutions.
6. Describe how a suspension is formed and name some common suspensions.
7. Describe the differences in appearance between solutions, suspensions and colloids.
8. Describe the differences between solutions, suspensions and colloids in terms of particles.
9. Identify, describe and outline everyday uses for the different methods of separating
insoluble substances:
· sedimentation (decanting);
· centrifuging;
· sieving;
· magnetic separation;
· filtering;
· electrostatic separation;
· gravity separation;
· froth flotation.