Convection & Evaporation

Question 1

What is convection? When does it happen?

Answer 1

Convection is the process of transferring heat through air/liquid currents and it happens when a fluid is heated. The particles gain energy causing them to move around/spread out more. This makes the area of the hot fluid less dense than the cold surroundings, so the hot fluid rises and pulls in cold fluid to replace it.

Question 2

What is the name for a closed system that can happen when convection takes place?

Answer 2

Convection current

Question 3

Can convection happen in solids? Explain your answer.

Answer 3

No, because the particles are in a fixed position so they cannot flow and move around.

Question 4

(T or F) Convection only takes place in gases and in liquids.

Answer 4

True

Question 5

(T or F) Evaporation only happens at a certain temperature.

Answer 5

False, evaporation can happen at any temperature

Question 6

Explain, step by step, how evaporation takes place.

Answer 6

• particles in liquids move around with different speeds
• these particles need enough energy to break through the surface of the liquid
• therefore, only the fastest particles escape
• they take heat energy with them so the liquid loses heat energy and cools