Q. 13. Composition of the nuclei of two atomic species and are given as under
Protons = 6 6
Neutrons = 6 8
Give the mass numbers of and . What is the relation between the two species?
As we know,
the mass number of an atom = No. of protons + No. of Neutrons
The mass number of X = No. of protons of X + No. of Neutrons of X
= 6 + 6
The mass number of Y = No. of protons of Y + No. of Neutrons of Y
= 6 + 8
As both X and Y have the same atomic number (6) but different numbers (i.e., 12 and 14 respectively), they are isotopes.