Meanings
nounmass number (plural mass numbers)
plural mass numbers
- physicalchemistryThe total number of protons and neutrons in an atomic nucleus. Symbol: A
Synonyms: atomic mass number, nucleon number
Synonyms & antonyms
nounThe total number of protons and neutrons in an atomic nucleus. Symbol: A
More synonyms by meaning
nounthe sum of the number of neutrons and protons in an atomic nucleus
Similar
Broader
mass unit
Also see
Synonym sets from Open English WordNet, CC BY 4.0.
Origin
Translations
Arabic عَدَد كُتْلِيّ
- عَدَد كُتْلِيّ (ʕadad kutliyy)number of protons and neutrons in an atomic nucleus
Bulgarian масово число
- масово число (masovo čislo)number of protons and neutrons in an atomic nucleus
Catalan nombre màssic, nombre de massa
- nombre màssicnumber of protons and neutrons in an atomic nucleus
- nombre de massanumber of protons and neutrons in an atomic nucleus
Chinese Mandarin 質量數 /质量数
- 質量數 /质量数 (zhìliàngshù)number of protons and neutrons in an atomic nucleus
Danish nukleontal
- nukleontalnumber of protons and neutrons in an atomic nucleus
Dutch massagetal
- massagetalnumber of protons and neutrons in an atomic nucleus
Finnish massaluku
- massalukunumber of protons and neutrons in an atomic nucleus
French nombre de masse
- nombre de massenumber of protons and neutrons in an atomic nucleus
German Massenzahl
- Massenzahlnumber of protons and neutrons in an atomic nucleus
Greek μαζικός αριθμός
- μαζικός αριθμός (mazikós arithmós)number of protons and neutrons in an atomic nucleus
Hungarian tömegszám
- tömegszámnumber of protons and neutrons in an atomic nucleus
Indonesian nomor massa
- nomor massanumber of protons and neutrons in an atomic nucleus
Italian numero di massa
- numero di massanumber of protons and neutrons in an atomic nucleus
Korean 질량수
- 질량수 (jillyangsu)number of protons and neutrons in an atomic nucleus
Latvian masas skaitlis
- masas skaitlisnumber of protons and neutrons in an atomic nucleus
Māori tau karihi
- tau karihinumber of protons and neutrons in an atomic nucleus
Polish liczba masowa
- liczba masowanumber of protons and neutrons in an atomic nucleus
Portuguese número de massa
- número de massanumber of protons and neutrons in an atomic nucleus
Russian массовое число́
- массовое число́ (massovoje čisló)number of protons and neutrons in an atomic nucleus
Spanish número másico, número de masa
- número másiconumber of protons and neutrons in an atomic nucleus
- número de masanumber of protons and neutrons in an atomic nucleus
Swedish masstal
- masstalnumber of protons and neutrons in an atomic nucleus
Thai เลขมวล
- เลขมวลnumber of protons and neutrons in an atomic nucleus
Ukrainian ма́сове число́
- ма́сове число́ (másove čysló)number of protons and neutrons in an atomic nucleus
Vietnamese số khối
- số khốinumber of protons and neutrons in an atomic nucleus
Cite this entry
APA
mass number. (n.d.). In WatkinsX Dictionary. Retrieved November 4, 2026, from https://dictionary.watkinsx.com/word/mass%20number
MLA
“mass number.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/mass%20number. Accessed November 4, 2026.
Chicago
WatkinsX Dictionary, s.v. “mass number,” accessed November 4, 2026, https://dictionary.watkinsx.com/word/mass%20number.
Source: mass number on Wiktionary, CC BY-SA 4.0.