Introduced by Bohr when only two quantum numbers were hypothesized, the shifting of a 4s electron to a 3d electron in copper is a notable violation of this rule.
A model developed by Kitaigorodskii that is used to predict the packing behavior of crystals is know by this term. Applying the more well known statement by this name to the Dirac-Fock has helped calculate the ionization potential of superheavy elements with 7p orbitals, and it is analogous to Maedlung's rule. Introduced by Bohr when only two quantum numbers were hypothesized, the shifting of a 4s electron to a 3d electron in copper is a notable violation of this rule. For 10 points, identify this principle which states that electrons fill in lower orbitals before they can use the higher orbitals, German for "building up" or "construction." 
A model developed by Kitaigorodskii that is used to predict the packing behavior of crystals is know by this term.
aufbau principle