The fixed amount of energy that a system described by quantum mechanics, such as a molecule, atom, electron, or nucleus, can have.
More example sentences
- This means that an atom with eight electrons in its outermost energy level is very stable.
- An electron in a lower energy level is both closer to the nucleus and has fewer electrons between itself and the nucleus.
- When an electron falls from a higher energy level to a lower energy level, a photon is given off.