Question

Which best describes nuclear fission?

Answer 1

Nuclear fission, subdivision of a heavy atomic nucleus, such as that of uranium or plutonium, into two fragments of roughly equal mass. The process is accompanied by the release of a large amount of energy. In nuclear fission the nucleus of an atom breaks up into two lighter nuclei.

Answer 2

Subdivison of an atom's nucleus that results in two fragments of roughly equal size. Energy is also released during said process.