Question

which of these are fundamentally electric potential energy, when considered at the microscopic scale? choose 2 answers: a chemical potential energy b gravitational potential energy c elastic potential energy d kinetic energy

Explanation:

• Option A (chemical potential energy): At the microscopic scale, chemical potential energy comes from the electric interactions between atoms and molecules (e.g., electron - proton interactions, intermolecular forces which are electrostatic in nature). So it is fundamentally electric potential energy.
• Option B (gravitational potential energy): Gravitational potential energy is due to the gravitational force between masses. Gravitational force is a different fundamental force from the electric force, so it is not electric potential energy.
• Option C (elastic potential energy): At the microscopic level, elastic potential energy in a material is due to the stretching or compressing of interatomic or intermolecular bonds, which are electrostatic in nature (the bonds are a result of electric forces between atoms/molecules). So it is fundamentally electric potential energy.
• Option D (kinetic energy): Kinetic energy is the energy of motion. It is related to the mass and velocity of an object ($K=\frac{1}{2}mv^{2}$) and has nothing to do with electric potential energy at the microscopic scale.

Answer:

A. chemical potential energy, C. elastic potential energy