Particle model of matter

Question 1

What is the equation for density?

Answer 1

density = mass divided by
volume

Question 2

What is internal energy?

Answer 2

Energy is stored inside a system by the particles (atoms and molecules) that make up the system. This is called internal energy. Internal energy is the total kinetic energy and potential energy of all the particles (atoms and molecules) that make up a system.

Question 3

How does heating change the energy stored in a system?

Answer 3

Heating changes the energy stored within the system by increasing the energy of the particles that make up the system. This either raises the temperature of the system or produces a change of state

Question 4

What is specific heat capacity?

Answer 4

The specific heat capacity of a substance is the amount of energy required to raise the temperature of one kilogram of the substance by one degree Celsius.

Question 5

What happens when a change of state happens in terms of latent heat?

Answer 5

The energy needed for a substance to change state is called latent heat. When a change of state occurs, the energy supplied changes
the energy stored (internal energy) but not the temperature.

The specific latent heat of a substance is the amount of energy required to change the state of one kilogram of the substance with no change in temperature.

Question 6

What is specific latent heat of a fusion?

Answer 6

change of state from solid to liquid

Question 7

What is specific latent heat of vaporisation?

Answer 7

change of state from liquid to
vapour

Question 8

Explain the arrangements of molecules in a gas:

Answer 8

The molecules of a gas are in constant random motion. The temperature of the gas is related to the average kinetic energy of the molecules.
Changing the temperature of a gas, held at constant volume, changes the pressure exerted by the gas