Answer:
For isotopes, the difference between the mass number and number of neutrons is constant.
Explanation:
Isotopes are atoms with the same atomic number but different mass numbers.
Number of neutrons in an atom can be obtained by subtracting the atomic number from the mass number.
So in other words , isotopes are atoms for which the difference between the mass number and number of neutrons is constant.
For example, Hydrogen,Deuterium and Tritium are isotopes of Hydrogen in which the difference between mass number and number of neutrons is 1.
