Answer:
If you add the masses of all the products after fission, they are LESS than the mass of the reactants.
Explanation:
A nuclear fission reaction is a radioactive reaction which in which a heavy nucleus spontaneously disintegrates into 2 lighter nuclei and some neutrons with a release of large amount of energy.
When nuclear fission occurs, a mass deficit between the decaying nuclei and the product occurs. It is this mass that actually yields the energy that is produced as a by product of the reaction.