Temperature Changes And Energy

Question 1

What are the particles in a solid like?

Answer 1

Regular arrangement
Vibrate around a fixed position
Sit very closely

Question 2

What are particles in a liquid like?

Answer 2

Randomly arranged
Move around eachother
Sit close together

Question 3

What are particles in a gas like?

Answer 3

Randomly arranged
Move quickly in all directions
Are far apart

Question 4

How can adding or removing energy change a materials state?

Answer 4

Heating a solid makes it melt from solid to liquid
Continued heating causes it to evaporate

Question 5

What is sublimation?

Answer 5

A solid going straight to a gas without being heated

Question 6

What is boiling?

Answer 6

An active process
Do actively apply energy to a liquid to turn it into a gas using a heater like a kettle

Question 7

What is evaporation?

Answer 7

A passive process of liquid turning into a gas
Liquid slowly absorbs energy from the surrounding area so some particles gain enough energy to escape the liquid

Question 8

What happens to particles in a change of state?

Answer 8

Number of particles don’t change just their arrangement
Total mass doesn’t change

Question 9

Why are changes in state physical changes?

Answer 9

Physical changes because the process can be reversed

Question 10

What may happen internally when a material is cooled or heated?

Answer 10

Chemical bonds between particles may form break or stretch. There is a change in chemical potential store

As the material heats up or cools down particles gain or loose speed. There is a change in thermal store

Question 11

What is internal energy?

Answer 11

Total amount of kinetic and chemical potential energy of all particles in the system

Question 12

What happens to particles when energy is given to raise the temperature?

Answer 12

Particles speed up and gain kinetic energy

Question 13

What happens to bonds when a substance melts or boils?

Answer 13

Energy is put into breaking bonds that hold particles together, which increases potential energy

Question 14

Where does energy go in change of state?

Answer 14

All energy will go to the thermal or chemical store

Question 15

What is temperature?

Answer 15

Measure of the average speed of particles. This is based on the kinetic energy of individual particles m

Question 16

What does heating water to water molecules?

Answer 16

They gain kinetic energy and speed up

Question 17

Why does it take more energy to raise the temperature of large amounts of water?

Answer 17

More molecules need to have their speed changed

Question 18

Why is it quicker to heat a block of lead than water?

Answer 18

Because led is a solid and particles are vibrating and vibrate faster when heated the particles are more likely to hit eachother and pass energy

Question 19

What is specific latent heat

Answer 19

Energy required to change the state of a 1kg of material without changing its temperature

Question 20

What is latent heat of fusion?

Answer 20

Amount of energy needed to melt or freeze the material at its melting point

Question 21

What is specific latent heat of vaporisation?

Answer 21

Amount of energy needed to boil or condense a material at its boiling point

Question 22

In a temperature-time graph what does a long horizontal line mean?

Answer 22

More energy has been used to cause a change of state
Equal to the latent heat