noun
- The sum of the number of neutrons and protons in an atomic nucleus.
- synonyms: nucleon number
WordNet 3.0 © 2006 by Princeton University
| APA | WordNet. (2010). mass number. Retrieved September 20, 2026, from http://smartdefine.org/mass_number/definitions/1244342 |
| Chicago | WordNet. 2010. "mass number" http://smartdefine.org/mass_number/definitions/1244342 (accessed September 20, 2026). |
| Harvard | WordNet 2010, mass number, Smart Define, viewed 20 September, 2026, <http://smartdefine.org/mass_number/definitions/1244342>. |
| MLA | WordNet. "mass number" 23 October 2010. Web. 20 September 2026. <http://smartdefine.org/mass_number/definitions/1244342> |