Question #e5346

1 Answer
Sep 29, 2016

Answer:

First you need #Z#, #"the atomic number"#.

Explanation:

And #"Mass number"-"Atomic number"# #=# #"Number of neutrons"#.

Both neutrons and nuclear protons are the massive particles of the atom, and both contribute to the mass of an isotope. You need both to make the determination of mass.