Question

If both the number of protons and number of neutrons are conserved in each nuclear reaction, in what way is mass converted into energy (or vice-versa) in a nuclear reaction?

Answer 1

First, we need to analyze the question is when I will give you the right answer. If both the number of protons and number of neutrons are conserved in each nuclear reaction, in what way is mass converted into energy (or vice-versa) in a nuclear reaction.

I would suppose that since binding energy contributes to mass, we say that the difference in the total mass of nuclei on the two sides gets converted into energy

Answer 2

The sum of masses of nuclei of product element is less than sum of masses of reactants and hence, loss of mass takes place during the reaction. This difference of mass of product element and reactant converts into energy and liberated in the form of heat.