Thermal Properties and Temperature

Question 1

What happens when materials are heated?

Answer 1

They expand (Increase in volume)

Question 2

Why do the different states of matter expand at different rates?

Answer 2

It is due to the forces between them, stronger attractive forces in solids are harder to break rather than gases’ weak bonds.

Question 3

How is thermal expansion applied?

Answer 3

1. Railways have Expansion Gaps
   
   1. Bridges have Expansion Gaps

Question 4

What is internal energy?

Answer 4

Internal energy is the total energy of all the particles, the higher the temperatures, the more energy.

Question 5

What is specific heat capacity?

Answer 5

c = Thermal Energy Required / Mass x Change in Temperature

Thermal Energy = C x Change in Temperature x Mass

Question 6

How is temperature affected by the change of states?

Answer 6

solid → liquid → gas

There will be plateus in the middle due to thermal energy being used to release the bonds.

Question 7

What is evaporation?

Answer 7

Evaporation is the change of state from liquid to gas. Evaporation is cooling, due to the most energetic particles escaping into the air.

Question 8

How does evaporation and boiling differ?

Answer 8

Boiling:

Occurs at a particular temperature

Fast

Takes Place Throughout the liquid

Constant Temp

External Energy Store Needed

Evaporation:

Occurs at any Temp

Slow

Only at Surface

No Bubbles

Changing Temp

External Source uneeded

Question 9

What is the rate of evaporation affected by?

Answer 9

1. Temperature
2. Surface area of liquid
3. Movement of air