Q2 of 94 Page 440

The mass number of a nucleus is equal to

This is because in a nucleus, the mass number is the sum of the total numbers of protons and neutrons together.

Thus (c) will be the correct answer as number of nucleons refers to the total number of protons and neutrons.

If three helium nuclei combine to form a carbon nucleus, energy is liberated. Why can’t helium nuclei combine on their own and minimize the energy?

The mass of a neutral carbon atom in ground state is:

As compared to ¹²C atom, ¹⁴C atom has,

The mass number of a nucleus is