Mass number
From Mass Spec Terms
| DRAFT DEFINITION |
| Mass number |
|---|
| The sum of the protons and neutrons in an atom, molecule or ion. |
| Considered between 2004 and 2006 but not included in the 2006 PAC submission |
| This is an unofficial draft definition presented for information and comment. |
Gold Book Entry
Total number of heavy particles (protons and neutrons jointly called nucleons) in the atomic nucleus. Also called nucleon number. Symbol m in mass spectrometry.
