excited state

An excited state is a condition where an atom or molecule has absorbed energy, causing its electrons to occupy higher energy levels than they normally do in a stable, ground state. Think of it like a ball sitting in a shallow valley (ground state). When energy is added, the ball is pushed up a hill (excited state). This state is temporary; eventually, the atom releases the excess energy (often as light) and returns to its original, more stable state. Excited states are important in processes like lighting, lasers, and energy transfer in various systems.