Definition of energy level in English:

energy level


  • The fixed amount of energy that a system described by quantum mechanics, such as a molecule, atom, electron, or nucleus, can have.

    • ‘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.’
    • ‘For instance, photons will share a particular energy level in a laser.’
    • ‘This higher energy level allows X-ray beams to pass straight through most of the soft material in the human body.’