Grotrian energy diagram

The Grotrian diagram in Figure 7.9 gives the energy levels for all the terms arising from the promotion of one electron in helium to an excited orbital. 

S. Bashkin and J.O. Stoner, Atomic Energy Levels and Grotrian Diagrams. North-Holland, Amsterdam, 1975. 

Figure 6.4. Grotrian diagram for the sodium atom, showing the energies of the atomic orbitals.

AAS is useful for the analysis of approximately 70 elements, almost all of them metal or metalloid elements. Grotrian diagrams correctly predict that the energy required to reach even the first excited state of nonmetals is so great that they cannot be excited by normal UV radiation (> 190 nm). The resonance hnes of nonmetals lie in the vacuum UV region. Commercial AAS systems generally have air in the optical path, and the most common atomizer, the flame, must operate in air. Consequently, using flame atomizers, atomic absorption cannot be used for the direct determination of nonmetals. However, nonmetals have been determined by indirect methods, as will be discussed in the applications section. 

The characteristic energy-level structure of these configurations is that of singlets or triplets, in accordance with the value 0 or 1 taken by S2. This structure is exhibited in the Grotrian diagram of Ybll 4f n 4d6s( D), KJ given in fig. 1.8. 

Figure 2.5 Energy levels and observed transitions in K. This type of diagram is commonly referred to as a Grotrian diagram. All of these low-lying energy levels arise from electron configurations of the type (1s) (2s) (2p) (35) (3p) (n/) = ...

C. E. Moore, Atomic Energy Levels, Circular 467, National Bureau Of Standards, vol. 1 (1949) S. Bashkin and J. 0. Stoner,Jr.,Atomic Energy Levels and Grotrian Diagrams (North-Holland, Amsterdam, 1975). 

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