1. Physical and chemical properties

Scandium, chemical symbol Sc, is the first external transition element of period IV. The 3d electron layer is filled. Like yttrium, scandium's outer electrons are distributed in the same way as the outer electrons of the lanthanides. Its chemical properties are therefore similar to those of the latter, and, like yttrium, scandium is thus associated with the rare earths.

• The main physical characteristics of scandium are as follows:

  • electronic structure: 3d ¹ 4s ² (lanthanum structure: 5d ¹ 6s ² ) ;

  • atomic number: 21 ;

  • number of isotopes and isomers: 19 (the isotope...