Matter - Quick Revision

Mass is the amount of matter an object has.

Volume is the amount of space an object takes up.

Small things take up less space, hence they have smaller volumes.

Solid
A solid has a definite shape. It will not change its shapre no matter how much it has been moved around. However, its shape will change if a force is applied on it.

A solid has a definite volume thus it cannot be compressed.

Liquid
A liquid has no definite shape. It fills the shape of the container that holds it.

A liquid has a definite volume and cannot be compressed. Its volume does not change when it is put into different containers.

Gas
A gas does not have definite shape.

A gas does not have a definite volume, hence it can be compressed.


Question: Cotton is in the solid state. But why cana boy squeeze a plastic bag fill of cotton so that the bag occupies less space?

Answer: There is trapped air in the cotton. The air escapes when a boy squeezes the bag so the bag occupies less space.