Number of Neutrons = Mass number - Atomic Number
mass number
mass number = protons + nuetrons
The Mass Number.
Isotope.
there are 12 nuetrons in an atom of magnesium
mass number = protons + nuetrons
In iron, there are 30 neutrons.
add the number of protons and nuetrons together
The most common isotope is 20
An isotope.
The sum of the number of the protons and neutrons in the nucleus of an atom is called as atomic mass.
Number of Protons & Electrons: 47 Number of Nuetrons: 61 http://www.purestcolloids.com/silver-atom-structure.htm