Everything we see around us is made of matter
The different kinds of matter are solid and liquid and gaseous matter. They are called the states of matter.
The symbols (s) for solid, (l) for liquid and (g) for gas are called state symbols. Later on we will encounter another symbol, (aq), which means ‘in aqueous (water) solution’.
Summary
Solids (s): fixed volume and shape
Liquid (s): fixed volume, shape changes
Gas (s): neither volume nor shape is fixed.
Liquids and gases are fluids.
| STATE | DESCRIPTION |
| Solid (s) | Has a fixed volume and a definite shape. The shape is usually difficult to change. |
| Solid (s) | Has a fixed volume. Flows easily, changes its shape to fill the shape of its container. |
| Gas (g) | Has neither a fixed volume nor a fixed shape: changes its volume and shape to fit the size and shape of its container. Flows easily; liquids and gases are called fluids. Gases are much less dense than solids and liquids. |
Pure substances
Most of the solids, liquids and gases which we see around us are mixtures of substances.
Crude oil is a mixture of petrol, paraffin, diesel fuel, lubricating oil and other liquids.
Air is a mixture of gases.
Some substances however consist of only one substance. Such substances are pure substances.