quantized energy levels

Quantized energy levels refer to specific, fixed amounts of energy that an atom or molecule can have. Rather than having any possible energy value, these systems can only occupy certain allowed states. Think of it like stairs; an electron can step only onto certain "rungs" and not in between. When it gains or loses energy, it jumps from one level to another, often by absorbing or releasing a photon (light particle). This concept is fundamental to understanding phenomena like atomic spectra, where each element has a unique set of energy levels, leading to characteristic light emissions.