Changes of state – Did you know?

Steam is made of invisible water vapour, which becomes visible as a white mist when it cools and condenses into tiny droplets. The air always contains some water vapour, and clouds form when high concentrations of this vapour condense into visible droplets.

What is steam primarily made of before it becomes visible?

• Condensed mist

• Invisible water vapour

• Ice crystals

• Liquid water

When does steam become visible as a white mist?

• When it evaporates

• When it condenses into droplets

• When it freezes

• When it is heated

What is always present in the air in small amounts?

• Liquid water

• Mist

• Ice

• Water vapour

How are clouds formed?

• By the evaporation of water

• By the freezing of water vapour

• By the melting of ice

• By the condensation of water vapour into droplets

What happens to water vapour to form visible clouds?

• It evaporates

• It condenses into droplets

• It freezes

• It sublimates