# what is matter?

MATTER:
Matter is anything that occupies space and has weight.

States of matter:

There are three states of matter namely:

Solids → e.g stone, ice, e.t.c

Liquids → e.g water, paraffin, e.t.c

Gases → e.g oxygen, nitrogen, e.t.c

Note:

Solids and liquids are incompressible, meaning that their volumes cannot be reduced by squeezing them.

Gases are compressible because of the large spaces between their molecules.

Change of state

Heating of matter
When a solid is heated, it changes to a liquid at constant temperature called melting point. The process is called melting or fusion.

When the liquid formed is heated further, the liquid changes to vapour at constant temperature called boiling point. The process is called boiling or evaporation.

Cooling of matter

When a gas or vapour is cooled, it condenses to a liquid at constant temperature called freezing point. The process is called condensation or liquefying.

When the liquid formed is cooled further, it changes to a solid at constant temperature called freezing point. The process is called freezing or solidifying.

Kinetic Theory of matter

The kinetic theory of matter states that:

Matter is made up of small particles called molecules or atoms that are in a state of constant random motion.

The speed of motion of the particles is directly proportional to the temperature.

The kinetic theory of matter can be proved by using:

(i) Brownian motion
(ii) Diffusion