Atoms electronic states

The trends in chemical and physical properties of the elements described beautifully in the periodic table and the ability of early spectroscopists to fit atomic line spectra by simple mathematical formulas and to interpret atomic electronic states in terms of empirical quantum numbers provide compelling evidence that some relatively simple framework must exist for understanding the electronic structures of all atoms. The great predictive power of the concept of atomic valence further suggests that molecular electronic structure should be understandable in terms of those of the constituent atoms. 

For atoms, electronic states may be classified and selection rules specified entirely by use of the quantum numbers L, S and J. In diatomic molecules the quantum numbers A, S and Q are not quite sufficient. We must also use one (for heteronuclear) or two (for homonuclear) symmetry properties of the electronic wave function ij/. ... 

Several characteristics of the metal beam have been studied in detail. It is well known that metal clusters and metal oxides are formed as a result of the ablation process. However, these potentially interfering species have been studied in detail130 and it has been concluded that they do not introduce any doubt as to the validity of the experimental results. Much more important than cluster or oxide formation are the atomic electronic state populations of the metal beams. For each metal reactant, these have been characterized using laser-induced fluorescence (LIF) excitation spectroscopy. For Y, only the two spin-orbit states of the ground electronic state (a Dz/2 and a D-3,/2) were observed.123... 

The optimized geometries of Cr clusters are given in Figure 10. 3 is composed of a dimer plus an atom The electronic structure of the dimer is little affected by the presence of the third atom, which remains in its atomic electronic state, leaving six unpaired electrons in the cluster. A new pair forms... 

F. Hund, "Zur Deutung der Molekulspektren. IV," ZP 51 (1928) 759795 R. S. Mulliken, "The Assignment of Quantum Numbers for Electrons in Molecules. II. Correlation of Molecular and Atomic Electron States," Physical Review 32 (1928) 761772 E. Hiickel, "Zur Quantentheorie der Doppelbindung,"... 

Electronic state of oxygen atom Electronic state of molecular 02 ... 

Burned that the total atomic relativistic energy is almost independent of the atomic electronic state and the chemical environment in molecules, which implies cancellation of relativistic effects in chemical processes. According to Kolas the correction of the total energy of Hit for relativistic effects amounts to -1.60 cm whereas with the dissociation energy it is only 0,14 cm. Data for H2 are presented in Table 1,3, This table also gives us evidence on the validity of... 

Life is a partial, continuous, progressive, multiform, and conditionally interactive self-realization of the potentialities of atomic electron states. 

The bathochromic shift in biology, as exemplified by the lobster crustacyanin case, is an amazing example of interactions of various molecules and of the relevance of atomic electron states as manipulated by those interactions. 

Empirically, the multiplicity M of a molecular or atomic electronic state inchcates die number of distinct states (sublevels) into which a beam of molecules or atoms in that state is resolved on passing through a strong magnetic field one (singlet). 

Two different levels / and k) that are connected by an optical transition may be split into closely spaced sublevels / ) and A >. A narrow-band laser that is tuned to the transition / ) km) between specific sublevels selectively depletes the level / ) and increases the population of the level km) (Fig. 5.7). Examples of this situation are hyperfine components of two rotational-vibrational levels in two different electronic states of a molecule or Zeeman sublevels of atomic electronic states. 

Mulliken, R. S. 1928a. The assignment of quantum numbers for electrons in molecules. 11. The correlation of molecular and atomic electron states. Physical Review 32 761-772. 

Hund s rules are applicable to molecular electronic states as well as atomic electronic states (which is partly why they are so useful). Therefore, the highest-multiplicity electronic state, the 2g state, is predicted to be the ground state. (It is, as determined experimentally by various means.) The 2g and Ag electronic states are excited states within the (tt ) electronic configuration of the diatomic molecule (see Figure 15.11). 

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