P6 - States of Matter

Question 1

P6 - Describe the arrangement of particles in a solid, liquid and gas.

Answer 1

Solid:

Atoms closely packed

Arranged in a regular pattern.

Atoms vibrate in fixed positions.

Liquid:

Atoms are close together.

Atoms not in a regular pattern.

Atoms can slide over one another.

Gas:

Atoms are well separated.

Atoms are arranged randomly.

Atoms move freely in all directions.

Question 2

P6 - How do you calculate the density of an object?

Answer 2

Density = mass / volume

Question 3

P6 - Explain what happens during a change in state

Answer 3

Horizontal (flat) parts to heating and cooling curves indicate a change in state.

When we heat a substance, the temperature remains constant because even though we are making the conditions hotter, the thermal energy added is used to break existing bonds between the molecules within the substance.

When we cool a substance, the temperature remains constant because even though we are making the conditions colder, thermal energy is released as new bonds are made.

Question 4

P6 - Explain what is meant by latent heat.

Answer 4

The amount of energy needed for a substance to change state.

It will depend on: the mass and type of substance as well as the size of forces that must be overcome.

Energy = mass x latent heat