Scandium Group Elements electron structures

Ans. Mendeleev had used the prefix eka- (Sanskrit word for first) to name elements whose existence he predicted, applying the prefix to a known element in the same periodic group as the predicted element. His eka-boron, eka-aluminum, and e a-silicon were later discovered, confirmed, and named scandium, gallium, and germanium. Elements 104 and 105 were predicted to have electronic structures analogous to Hf and Ta. 

On the electronic structure of the carbides of the group III elements (scandium, yttrium and the lanthanides), only a few theoretical investigations are available. The bond structure of ScC was calculated by Schwarz et al, (1969) using the augmented-plane-wave method, Ivashchenko et al, (1984) applied the same method to YC and presented the densities of states for YC,, = O-Sj 0-7 and 0.6, which were calculated by using the coherent potential approximation. The results have been used to analyze the stability of the compounds. However, both calculations (Schwarz et al. 1969, Ivashchenko et al. 1984) were not performed self-consistently. Zhukov et al. (1987)... 

Electronic Structures. Almost all the physical properties and chemical behavior of the rare earth elements find a logical explanation in terms of their electronic structures. Scandium, yttrium, lanthanum, and actinium are the first members, respectively, of the first, second, third, and fourth transition sequences of elements. In other words, each such element marks the beginning of an inner building where a stable group of 8 electrons is expanding to a completed (or more nearly complete) group of IS. This situation is illustrated for the first transition sequence. 

THE RARE EARTH elements are those from atomic numbers 57 (lanthanum) to 71 (lutetium) inclusive and elements 21 (scandium) and 39 (yttrium). They represent the largest group of chemically similar elements, but their physical properties differ markedly due to subtle features of electronic structure. Because of the similarity between... 

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