Topic 1 - States of Matter

Question 1

2.1 - Describe the arrangement, movement and relative energy of particles in different states

Answer 1

Gas particles are arranged randomly and far apart, the particles move fast in all directions with high energy.
Liquid particles are arranged randomly but close together, the particles move around eachother with less energy.
Solid particles are arranged regularly and close together, the particles vibrate in fixed positions.

Question 2

2.2 - What physical changes happens to particles during changes of state?

Answer 2

When a gas becomes a liquid condensation occurs.
When a liquid becomes a solid freezing occurs.
When a solid becomes a liquid melting occurs.
When a liquid becomes a gas evaporation occurs.
When a gas becomes a solid deposition occurs.
When a solid becomes a gas sublimation occurs.

Question 3

2.3 - Explain the physical changes in arrangement, movement and energy that take place during changes of state

Answer 3

Solids have lots of weak forces of attraction between particles, during melting some of these forces are overcome to form liquids.
The remaining attractive forces in a liquid are overcome by energy transfers from the surroundings to the particles during evaporation. ( gaining energy as gas particles have high energy )
During condensing, some attractive forces are formed between particles.
However, during freezing many attractive forces are formed by energy being transferred from the particles to the surrounding ( losing energy )

Question 4

2.4 - Suggest how to predict the physical state of a substance given suitable data

Answer 4

If the substances’ temperature ( water at 50° ), melting ( 0° ) and boiling point ( 100° ) is given.
The substance is a solid if the temperature is below the melting point.
The substance is liquid if temperature is between melting and boiling point.
The substance is a gas if temperature is higher than its boiling point.
So water is a liquid at this temperature.