Atomic theory

The atomic theory is a theory of the nature of matter. It states that all matter is composed of atoms. The philosophical background of the atomic theory is called atomism. This definition is valid for the matter commonly surrounding us. Strictly speaking it is not valid in plasmas or other particular environments characterized for instance by very large pressure (e.g. neutron stars).

See also

• Timeline of quantum mechanics, molecular physics, atomic physics, nuclear physics, and particle physics
• Timeline of thermodynamics, statistical mechanics, and random processes
• Timeline of chemical element discovery