Solids

Steel, plastic and wood are solids at room temperature. Ice is solid water. The particles in a solid are:

• close together
• arranged in a regular way

Particles in a solid

Strong forces, called bonds, attract the particles towards each other. This means that the particles in a solid:

• can vibrate in a fixed position
• cannot move from place to place

The table shows some of the properties of solids and why they are like this:

PropertyReason They have a fixed shape and cannot flow The particles cannot move from place to place They cannot be compressed (squashed) The particles are close together and have no space to move into

Solids such as concrete are useful for buildings and their foundations because they cannot be compressed.

Liquids

Mercury, petrol and water are liquids at room temperature. The particles in a liquid are:

• close together
• arranged in a random way

Particles in a liquid

The particles in a liquid can:

• move around each other

The bonds in a liquid are strong enough to keep the particles close together, but weak enough to let them move around each other.

The table shows some of the properties of liquids and why they are like this:

PropertyReason They flow and take the shape of the bottom of their container The particles can move around each other They cannot be compressed (squashed) The particles are close together and have no space to move into

Liquids are useful in car brake…