Question

Composition of the nuclei of two atomic species X and Y are given as under 

	X	Y
Protons	6	6
Neutrons	6	6

Give the mass numbers of X and Y. What is the relation between the two species?

Answer 1

Mass number of X = Number of protons + Number of neutrons = 6 + 6 = 12

Mass number of Y = Number of protons + Number of neutrons = 6 + 8 = 14

These two atomic species X and Y have the same atomic number, but different mass numbers. Hence, they are isotopes.