Answer: Option (b) is the correct answer.
Explanation:
Isotopes are the species that have same atomic number.
For example, \(^{12}_{6}C\) and \(^{13}_{6}C\) are isotopes. As both of them has 6 protons and there are 6 neutrons in \(^{12}_{6}C\). There are 7 neutrons in \(^{13}_{6}C\).
It is known that atomic number is the total number of present in an atom. Whereas mass number is the sum of total number of protons and neutrons present in an atom.
Atomic mass = no. of protons + no. of neutrons
Therefore, we can conclude that when two elements are isotopes then the isotopes of a particular element differ as they have less or more neutrons.
