Chemistry/Content/Atoms & Molecules

All matter is made of atoms. Atoms are the smallest bits of the matter we are used to thinking about. There are just over 100 different chemical types of atoms. These are called elements.

History of the atom. The greek philosopher Democritus was the first to state that all things are made up of atoms.

It was not until over 1000 years later that John Dalton expanded on Democritus' notion. Dalton's Atomic Theory summarizes what John Dalton had hypothesized. We now know that not all of Dalton's Atomic Theory is true.