Mass number

The mass number is the sum of the number of neutrons and protons in the nucleus of an atom.[1] The atomic number is determined by the isotopic atomic weight.

## See also[edit]

* Atomic number
* Atomic mass

## References[edit]

1. ↑ Wile, Jay L. Exploring Creation With Physical Science. Apologia Educational Ministries, Inc. 1999, 2000.