Which of the following forms of energy is reliant on the motion of molecules?

Heat energy, also known as thermal energy, is fundamentally dependent on the motion of molecules. It refers to the energy generated from the movement of atoms and molecules within a substance. As the temperature of an object increases, the kinetic energy of its molecules also rises, causing them to move more vigorously. This molecular motion results in the transfer of heat and the manifestation of thermal energy.

In contrast, electrical energy involves the flow of charged particles, typically electrons, rather than molecular motion. Nuclear energy arises from the interactions within atomic nuclei, including processes such as fission or fusion, rather than molecular activity. Chemical energy is associated with the bonds between atoms in a compound, and while it can be released or absorbed during chemical reactions, it does not directly relate to the molecular motion that characterizes heat energy. Thus, the reliance of heat energy on the motion of molecules makes it the correct choice in this scenario.