Changes Of State

Question 1

What happens during a change of state and what is the result of this?

Answer 1

Energy is used to overcome the forces between particles. As a result, the particles gain kinetic energy and move further apart. The forces of attraction between the particle are weaker the further apart they are

Question 2

What is evaporation?

Answer 2

The change of state between liquid and gas

Question 3

What is boiling?

Answer 3

Boiling occurs at a fixed temperature, the boiling point

Question 4

What temperature can evaporation occur at?

Answer 4

Any temperature, even if it’s below the boiling point

Question 5

Which particles can evaporate below the boiling point?

Answer 5

Only particles with sufficient energy near the surface of the liquid

Question 6

What makes evaporation increase and why?

Answer 6

Increased temperature as the average energy of the particles increases

Question 7

What happens when a liquid reaches its boiling point?

Answer 7

Bubbles of gas form within the liquid

Question 8

Describe the change of state from a solid to a liquid

Answer 8

• When a solid becomes a liquid, the particles gain energy.
• Particles move more quickly
• Energy is used to overcome the forces between the particles
• Particles move away from their fixed positions
• Particles are now randomly arranged and can move over each other