For Students
The chemical, metallurgical, and physical behaviours of the rare earths are governed by the electron configuration of these elements. In general, these elements are trivalent, R3+, but several of them have other valences. The number of 4f electrons of each lanthanide is given in the table of the number of 4f electrons and ionic radii for the R3+ ion. The 4f electrons have lower energies than and radially lie inside the outer three valence electrons (i.e., 4f electrons are “localized” and part of the ion core), and thus they do not directly participate in the bonding with other elements when ...(100 of 11935 words)