Excerpt - page 130: "... Also, the failure of classical physics to quantify energylevels of atoms or molecules has been at the origin of quantum mechanics where light ..."
Excerpt - page 9: "... complexes When considering the ways in which electrons can occupy energylevels of an atom, ion or molecule, Hunds rule states that the electronic configuration with the lowest ..."
Excerpt - page 985: "... absorption and lumines- cence, need not involve a transition in energy between quantized energylevels in atoms or molecules, ..."
Excerpt - page 78: "... However, the notion of discrete energylevels for atoms and molecules of whatever complexity became firmly established. It received striking confirmation ..."
Excerpt - page 26: "... When two atoms of hydrogen approach each other, the two atomic orbitals combine to form a bonding molecular orbital V b, which is characterised by a lower energy than that of the two atomic orbitals (Is) and an antibonding molecular orbital V., which has a higher energylevel ..."
Excerpt - page 477: "... atomic oscillators. 18.2 Atomic Oscillators Atomic oscillators use the quantized energylevels in atoms and molecules as the source of their resonance frequency. ..."
Excerpt - page 39: "... atomic clock A very accurate clock that uses the precise energy difference (and therefore the frequency of photons at resonance) between )energylevels in an atom or molecule. ..."
