A rigid container holds a fixed volume of air. The container is heated. How will the pressure of the air change?

A container is fitted with a piston that allows the pressure on the air in the container to be changed. The piston is pulled outwards so that the volume of the air increases. How will the pressure of the air change?

A small container of water is placed in an oven at $90°\mathrm{C}$. The water soon disappears. What name is given to process by which a liquid becomes a gas at a temperature below its boiling point?

A small container of water is placed in an oven at $90°C$. The water soon disappears. Why must energy be supplied to a liquid to turn it into a gas? In your answer, refer to the particles of the liquid and the forces between them.

Solids, liquids and gases have different properties. The list below gives some of them.

Copy that table and use descriptions from the list to complete it. Any description may be used more than once if appropriate. Two spaces have been filled in to help you.

The diagram represents the path taken in air by a smoke particle, as seen in a Brownian motion experiment. The smoke particles can be seen through a microscope, but the air molecules cannot.

State what causes the smoke particles to move like this.

The diagram represents the path taken in air by a smoke particle, as seen in a Brownian motion experiment. The smoke particles can be seen through a microscope, but the air molecules cannot.

What conclusions about air molecules can be drawn from this observation of the smoke particles?

A can, containing only air, has its lid lightly screwed on and is left in strong sunlight.

State what happens to the pressure of the air in the can when it gets hot.