Correct option is C.
Explanation: Chemical energy is the energy which is related to the chemical bonds of atoms and molecules. It is released in the chemical reaction.
Option A is related to the kinetic energy of the atom because the atom is in motion.
Option B is related to the nuclear energy of the atom as it is explaining about the nucleus of the atom.
Option C is related to the chemical energy of the molecule as there is the formation of a bond between two atoms.
Option D is related to the kinetic energy of the atom as we know that the electrons are in constant motion.