Topic 3: Particle Model of Matter.

Question 1

What is Density defined to be?

Answer 1

The mass per unit volume.

Question 2

What is the equation for Density?

Answer 2

Density = Mass / Volume.

Question 3

What does Density depend on?

Answer 3

How far / spaced out particles are.

Question 4

Why do solids and liquids have similar densities?

Answer 4

The space doesn’t change between the particles. Liquids often have lower densities except Ice and Water.

Question 5

What is the density of gas like?

Answer 5

The spacing between atoms increases x10 as the particles have lots of energy to move.

Question 6

What is the change of state called when a Solid becomes a Gas?

Answer 6

Sublimation is when a solid goes straight to a gas.

Question 7

Are changes of state reversible?

Answer 7

The physical changes are reversible.

Question 8

What is Specific Heat Capacity?

Answer 8

The amount of energy required to raise the temp of 1kg by 1c.

Question 9

What is the equation for change in thermal energy?

Answer 9

Mass x Specific Heat Capacity x Temp Change.

Question 10

What is Specific Latent Heat?

Answer 10

The amount of energy needed to change the state of 1kg of a substance without a temp change.

Question 11

What is the equation for energy for a change of state.

Answer 11

Mass x Specific Latent Heat.

Question 12

When Melting and Evaporation what happens to energy.

Answer 12

Energy is absorbed when melting and evaporating.

Question 13

When Freezing and Condensing what happens to energy.

Answer 13

Energy is released when freezing and condensing.

Question 14

What is related to the kinetic energy of molecules.

Answer 14

The temperature is related to the Ke of molecules.

Question 15

If there is a Higher temp of particles what does it result in.

Answer 15

The higher temp, the higher the Kinetic energy of the particles so faster average speed of molecules.

Question 16

What happens when molecules collide with the wall of their container?

Answer 16

The molecules exert a force on the wall. This is called pressure.

Question 17

What is pressure.

Answer 17

The total force of particles on the wall of a sealed container.

Question 18

What does an increase in volume do to pressure in a sealed container.

Answer 18

It will decrease the pressure as particles will have further to go around so less chance of colliding with wall.

Question 19

What does a temp rise in a sealed container do to pressure?

Answer 19

A temp rise gives energy to particles thermal store which is then shared to the kinetic store and they move faster thus increasing pressure.