With the help of Tab. Is given below, find out the mass numbers of oxygen and sulphur atoms:

The mass number is defined as the sum of the total number of protons and neutrons present in the nucleus of an atom.

(i) Mass number of oxygen = No. of protons + No. of neutrons = 8 + 8 = 16

Mass number of Oxygen is 16

(ii) Mass number of sulphur = No. of protons + No. of neutrons = 16 + 16 = 32

Mass number of sulphur is 32