Question

What is meant by saying that atomic mass of calcium is 40?

Answer 1

It means one Mole of calcium weighs 40g.

Answer 2

Explanation:

Atomic mass is also known as mass number. It means the total number of protons plus the total number of neutrons present in an atom.

Whereas atomic number means the number of protons present in an atom.

For example, the atomic mass of calcium is 40 ant its atomic number is 20. So, there are 20 protons in a calcium atom. The atomic mass will be as follows.

          Atomic mass = number of protons + the total number of neutrons

                                 = 20 + 20

                                 = 40