Nuclear energy and chemical energy

1)Nuclear Energy is released by the splitting (fission) or merging together (fusion) of the nuclie of atom whereas Chemical energy is the energy released or consumed due to associations of atoms in molecules and various other kinds of aggregates of matter.

2)Nuclear energy is based on the mass energy equivalece  relationship. The nuclear mass converts into energy,whereas chemical energy is produced by the is the energy due to associations of atoms in molecules and various other kinds of aggregates of matter.