Chapter 3 Atom Structure

1.25 Class Exercises

Multiple Choice

1 Nitrogen is heated in a balloon, which expands slightly.

Which statements about the molecules of nitrogen are correct?

1 They move further apart.

2 They move more quickly.

3 They remain the same distance apart.

4 Their speed remains unchanged.

• A 1 and 2

• B 1 and 4

• C 2 and 3

• D 3 and 4

Multiple Choice

3 Explain the meaning of "expands slightly".

• 剧烈爆炸

• 略微膨胀

• 轻微爆炸

• 剧烈膨胀

Multiple Choice

4 Heating a liquid causes it to become a vapour.

What happens to the molecules of the liquid during this process?

• A the molecules

  become bigger

• B the molecules move

  further apart

• C the molecules move

  closer

• D the molecules

  become smaller

Multiple Choice

5 Some sugar is dissolved in water.

Which diagram shows how the particles are arranged in the solution?

Multiple Choice

6 Which stages occur in distillation?

• A condensation then evaporation

• B condensation then filtration

• C evaporation then condensation

• D filtration then evaporation

Multiple Choice

7 The diagrams show the nuclei of four different atoms.

• A Q and R

• B Q and T

• C R and S

• D S and T

Multiple Choice

8 Which atom has twice as many neutrons as protons?

Multiple Choice

Which change takes place when an atom becomes a positive ion?

• An electron is added.

• An electron is removed.

•  A proton is added.

• A proton is removed.