Mass-number Synonyms
The total number of protons and neutrons in the nucleus of an atom. For example, nitrogen has 7 protons and 7 neutrons in its nucleus, giving it a mass number of 14. Isotopes of elements are distinguished by their mass number; for example, carbon-12 and carbon-14 have mass numbers of 12 and 14 respectively.
Synonyms:
- atomic-mass
- atomic-weight
- atomic-number
- atomic volume
- nucleon-number
The sum of the number of neutrons and protons in an atomic nucleus
(Noun)
Synonyms:
- nucleon-number