John Dalton

Definition

John Dalton was a British scientist who proposed the atomic theory, which states that all matter is composed of atoms, and these atoms cannot be created or destroyed but only combined and separated.

Related terms

Atomic Mass Unit (AMU): A unit used to express atomic and molecular weights, based on 1/12th of the carbon-12 atom's mass.

Chemical Reaction:

A process that leads to the transformation of one set of chemical substances into another.

Molecule:

The smallest particle in a chemical element or compound that has the chemical properties of that element or compound.