Question

Periodic table of elements with atomic mass rounded to integer

Answer 1

Definition of Mass Numbers: All atoms have a mass number which is derived from calculating the sum of the total number of neutrons and protons in an atomic nucleus of a particular atom.

Mass Numbers = (Number of Protons) + (Number of Neutrons)

Mass Numbers - Atomic Weight

It is necessary to establish the atomic weight to enable you to establish the Mass Number. The atomic weight or mass is, basically, a measurement of the total number of particles in an atom's nucleus. Using the Mass Number you will be able to calculate the number of Neutrons in an atom.