Composition of the nuclei of two atomic species X and Y are given as under
`{:(,X,Y),("Protons "=,6,6),("Neutrons "=,6,8):}`
Given the mass number of X and Y. What is the relation between the species ?

Explanation

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 have same atomic number but different mass number. Hence they are isotopes.