Answer : The correct option is, It becomes unstable.
Explanation :
Isotope : It is defined as the element that have the same number of protons but have the different number of neutrons of each of the atom.
As we know that, hydrogen element has three isotopes which are hydrogen, deuterium, and tritium. They have the same number of protons but have the different number of neutrons of each of the atom.
Hydrogen has 1 proton and 0 neutron, deuterium has 1 proton and 1 neutron and tritium has 1 proton and 2 neutrons.
That means, they have same atomic number but different mass number due to number of neutrons.
As the number of neutrons increases, the mass increases and the atoms becomes very massive that means the force holding then together become unstable and they break apart.
Hence, the correct option is, It becomes unstable.
