particle model of matter

What happens to a gas that is trapped in a container that cannot expand?

The volume of the gas is fixed and the pressure inside the container increases.

In a closed system ,changes in state won’t change the mass at all.Why is this the case?

The number of particles remain the same

When heat is added,the particles move around faster and have enough energy to break the bonds altogether.Which change of state does this describe ?

Boiling

Which change of state is being described below ?

“ As heat is added to a system, the particles vibrate more and more until they have enough energy to break free if their bonds.This allows the particles to move freely”.

Melting

What is density a measure of ?

How much mass a substance has , per unit of its volume.

What are the units of density?

Kg/m³

Which of these methods are used to reduce the uncertainty in experimental measurements of density?

1. Take multiple measurements then calculate the mean .

2. When measuring the density of liquids,use a larger volume of liquid .

During boiling , what does heat energy do to the particles?

The substance changes state from a liquid to gas via boiling.During boiling heat energy is used to break the forces holding the particles together.

1.What specific latent heat refers to when a substance changes from a solid to a liquid ( or vice versa)?

2.What specific latent heat refers to when a substance changes from a liquid to a gas ( or vice versa)?

1. fusion

2. Vaporisation

What is the formula for specific latent heat?

E=mL

What causes a flexible container to expand?

An increase in the force in the walls of the container.

Describe the motions of particles in a solid ?

Particles vibrate and they are in a fixed position.

Describe how the motions of particles in a gas changes as it’s heated?

Gas particles contain Kinetic energy, causing the average particle speed to increase.