G
o
o
g
l
e
×
Please click
here
if you are not redirected within a few seconds.
All
Images
Books
Videos
Maps
News
Shopping
Search tools
Any time
Any time
Past hour
Past 24 hours
Past week
Past month
Past year
All results
All results
Verbatim
Mass number
View all
The mass number, also called atomic mass number or nucleon number, is the total number of protons and neutrons in an atomic nucleus. It is approximately equal to the atomic mass of the atom expressed in atomic mass units.
Wikipedia
Symbol
:
symbol A