Science glossary film: Atomic number

The number of protons in the nucleus of an atom. It defines which chemical element the atom is considered to be. Only elements with atomic numbers from 1 to 92 occur naturally in significant amounts. But since about 1940, atoms with higher atomic numbers have been created by artificial means, so that around 118 elements have been observed so far.

It defines which chemical element the atom is considered to be. Only elements with atomic numbers from 1 to 92 occur naturally in significant amounts. But since about 1940, atoms with higher atomic numbers have been created by artificial means, so that around 118 elements have been observed so far.