Other Atoms and the Aufbau Principle

Unless otheiwise noted, all art on this page is Cengage Learning 2014. 

FIGURE 12.4 The effect of more than one electron on the electronic energy levels of an atom. For hydrogen-like atoms, all of the energy levels with the same principal quantum number n are degenerate. For atoms having more than one electron, the shells are separated by the quantum number as well. (Energy axis is not to scale.) 

Electron configurations are rather abbreviated when compared to the more complete Slater-determinant form of the antisymmetric wavefunction. Compare the electron configuration of Be with the Slater-determinant form of for Be. 

The electron configuration for Be, given above, is simply Is 2s. Using the rule from above for constructing Slater determinants, the more complete is 

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