States of matter (IGCSE)

In which changes do the particles move further apart?

• W and X

• W and Z

• X and Y

• Y and Z

Diagrams X, Y and Z represent the three states of matter.

Which change occurs during boiling?

• X to Y

• Y to Z

• Z to X

• Z to Y

Which change of state takes place during evaporation?

• gas to liquid

• liquid to gas

• liquid to solid

• solid to gas

In which process do particles move closer together but remain in motion?

• condensation

• diffusion

• evaporation

• freezing

Imagine a sugar lump in a cup of tea. Which two processes must happen to spread the sugar evenly in the tea?

• Diffusion, dissolving

• Dissolving and diffusion

• Dissolving and melting

• Melting and diffusion

Which statement is an example of diffusion?

• A kitchen towel soaks up some spilt milk.

• Ice cream melts in a warm room.

• Pollen from flowers is blown by the wind.

• The smell of cooking spreads through a house.

A few drops of perfume were spilt on the floor. A few minutes later the perfume could be smelt a few metres away. Which two processes had taken place?

• distillation and condensation

• distillation and diffusion

• evaporation and condensation

• evaporation and diffusion

Two gas jars each contain a different gas. The gas jars are connected and the cover slips are removed. The diagram shows what happens to the particles of the gases.

Which process has occurred?

• chemical reaction

• condensation

• diffusion

• evaporation

A liquid is heated until it boils.

Which result shows that the liquid in the test-tube is pure water?

• Condensation forms at the top of the test-tube.

• Steam is produced.

• The thermometer reads 100°C.

• There is nothing left behind in the test-tube.

A gas jar of bromine vapour and a gas jar of air are set up as shown in diagram 1. The glass slide is removed. Diagram 2 shows the appearance of the gas jars after one hour.

Which statement explains why the bromine and air mix together?

• Bromine is denser than air.

• Bromine is lighter than air.

• Bromine molecules moved upwards and molecules in air moved downwards.

• Molecules in bromine and air moved randomly.