the measure of the number of units, such as atoms, molecules, or ions of which all matter is made

In science, matter can be defined as anything that has mass and occupies space. Therefore, any physical object that is found on planet Earth is typically composed of matter.

Matter are known to be made up of atoms and as a result has the property of existing in states. The three (3) classical states of matter are;

1. Gas: is the state of matter in which the physical substance has no definite shape or volume and as a result fills all available space. Also, gases are easily compressible and can flow. Examples of gases are hydrogen, oxygen, argon, nitrogen etc.

2. Solid: is the state of matter in which the physical substance has a definite shape and fixed volume but not compressible. Examples of solids are pen, screwdriver, television, car etc.

3. Liquid: is the state of matter in which the physical substance can be poured and it takes the shape of its container. Also, liquids generally have a definite volume. Examples of liquids are urine, water, milk, blood etc.

Particles of matter can be defined as the measure of the number of units, such as atoms, molecules, or ions of which all matter is made. These particles of matter are typically tiny, minute or incredibly small and as such can not be seen with the naked eye. Also, the particles of matter are usually in a continual state of motion and are primarily held together by a bond energy.

Additionally, the four (4) properties that are peculiar to matter are: flow, volume, shape and compressibility.