What does einstein's famous equation for nuclear energy, e = mc2, mean?

some mass and energy are lost in a nuclear reaction.

mass and energy are destroyed in a nuclear reaction.

some mass is converted into energy in a nuclear reaction.

mass and energy are produced in a nuclear reaction.

Some mass is converted into energy in a nuclear reaction. Hope this helps!

Answer;

Some mass is converted into energy in a nuclear reaction.

Explanation;Nuclear fission and nuclear fusion are the two types of nuclear reactions. Nuclear fusion involves the combining of two small nuclei to form a larger nuclei coupled with the release of energy. Nuclear fission on the other hand involves the splitting of a heavy larger nuclei to yield smaller nuclei and is also coupled with the release of energy.In both nuclear fission and nuclear fusion reactions, energy is converted to mass.In nuclear fission, the resultant products have a slightly smaller nuclear mass as compared to heavy nucleus. This difference in mass is because some mass is converted to energy during the fission.Similarly in nuclear fusion some of the mass of the initial nuclei is converted into energy in the form of heat or light.