Alkali energy level diagram

Atomic Systems. Many atomic species may be modeled as three-level systems. Figure 2 illustrates the energy level diagram for sodium. Other alkali and alkaline metals behave in a similar manner. 

Fig. 2.4. Energy level diagram for the alkali atoms, compared with the energy levels of the excited states of H. The hydrogenic energies are indicated by horizontal dashed lines across the figure. The alkalis are arranged from left to right in order of increasing atomic number. All the levels are doublets, but most of them are so close that they do not show on the present energy scale (after H.E. White [26]).

One of the most instructive energy level diagrams in the whole of atomic physics is plotted in fig. 2.4, which shows the comparison between the energy levels of the ground and first excited states of the alkali atoms and the excited states of H. 

Fig. 2.8. Energy level diagrams for Cu, Ag and Au, all of which have one outer electron, drawn so as to emulate the trend for the alkalis. Note that the ordering of the atoms does not follow atomic numbers, and that core-excited configurations (plotted as circles and denoted with a star) appear amongst the low-lying excited Rydberg states (based on data from C.E. Moore [23]).

Fig. A.10 Potential energy diagrams of atoms chemisorbed on jellium in the resonant level model. The situation under (a) corresponds to Figure A.9. In (b) the adatom has a low ionization potential and consequently it donates charge to the metal (as with alkalis on metal), whereas in (c) the adatom has a high electron affinity such that it becomes negatively charged (as with fluorine on metals).

Table 8.3 shows the partial orbital diagrams and ground-state electron configurations for the 18 elements in Period 4 (again with filled inner levels in brackets and the sublevel to which the last electron has been added in colored type). The first two elements of the period, potassium and calcium, are the next alkali and alkaline earth metals, respectively, and their electrons fill the 45 sublevel. The third element, scandium (Z = 21), is the first of the transition elements, those in which d orbitals are being filled. The last electron in scandium occupies any one of the five 3d orbitals because they are equal in energy. Scandium has the electron configuration [Ar] 4s 3d. ... 

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