Condensation and Evaporation.

Question 1

What happens to particles when gas cools?

Answer 1

The particles slow down and lose kinetic energy. Attractive forces between the particles pull them closer together.

Question 2

What is condensation?

Answer 2

When gas turns to liquid.

Question 3

Explain the process of condensation.

Answer 3

• If the temp is cold enough and the gas particles are close together than condensation takes place, the gas becomes a liquid.
• Water vapour in the air condenses when it comes into contact with cold surfaces.
• Steam from kettle is invisible water vapours condensing to form water droplets as it spreads into cooler air.

Question 4

What is evaporation?

Answer 4

When liquid turns to gas.

Evaporation is when particles escape from a liquid.

Question 5

Explain the process of evaporation.

Answer 5

• Particles can evaporate from a liquid at room temperature that are lower than the liquids boiling point.
• Particles near the surface of a liquid can escape if:
  1. they are travelling in the right direction to escape the liquid
  2. they are travelling fast enough (they have enough kinetic energy) to overcome attractive forces of the other particles in the liquid.