Explain the difference between atomic number, mass number and atomic mass?

Answer 1

Atomic number is the number of protons. this number gives the identity of the element, such as carbon or oxygen. Mass number is the number of protons and neutron in a specific isotope or atom. Mass number is always a whole number. The atomic mass is the average mass of a particular element. It is an average and therefore not a whole number. For example, carbon has two common isotope Carbon-12 and Carbon-14. The number are mass numbers. But the atomic mass from the periodic table is a decimal like 12.011