In quantum mechanics, an energy level is a quantized state of an atom or molecule where it can exist. It represents the potential energy of the particle and determines how likely it is to transition between different states.
Related terms
Quantum Mechanics: The branch of physics dealing with atomic and subatomic systems which describes nature at the smallest scales of energy levels of atoms and subatomic particles.
Potential Energy: The stored energy that an object has because of its position or state.