Scientists classify matter in a number of ways. First, all matter is classified at the atomic level; atoms are classified as electrons, protons or neutrons. Electrons have a negative charge, protons have a positive charge and neutrons are neutral. After matter is classified at the atomic level, it is classified as either a mixture or a solution.
A chemical test is used to determine whether matter is a substance or a solution. A substance is a mixture if it can be separated by chemical means. Mixtures are either homogeneous, heterogeneous or colloidal. A homogeneous mixture is classified as uniform and the matter mixes or dissolves together. On the other hand, a heterogeneous mixture contains matter that separates. A colloidal mixture is determined by using the Tyndall effect. When a light is placed in front of a substance and the light does not pass through the substance, this result is known as the Tyndall effect. A colloidal substance can also be identified by thickness.
If matter cannot be separated by chemical means, it is classified as a substance. Substances are either an element or a compound. Elements contain a single type of atom, and compounds contain more than one type of atom.