mass number

noun

Definition of mass number

: an integer that approximates the mass of an isotope and designates the number of nucleons in the nucleus

Keep scrolling for more

Learn More about mass number

Dictionary Entries near mass number

Mass Observation

mass of mercury

mass of the catechumens

Statistics for mass number

Look-up Popularity

Time Traveler for mass number

The first known use of mass number was in 1923

See more words from the same year

Keep scrolling for more

More Definitions for mass number

mass number

noun

Medical Definition of mass number

: an integer that approximates the mass of an isotope and that designates the number of nucleons in the nucleus the symbol for carbon of mass number 14 is ¹⁴C or C¹⁴ — compare atomic mass

Comments on mass number

What made you want to look up mass number? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

rebuff

to reject or criticize sharply

Test Your Vocabulary

Words from Greek and Roman Mythology Quiz

Boreal comes from the name of the ancient Greek god of which wind?

Can you spell these 10 commonly misspelled words?

TAKE THE QUIZ

Word Winder's CrossWinder

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ

Words at Play

Ask the Editors

Word Games