Scandium is a soft, silvery-white metallic element with an atomic number 21, and is technically a light transition metal. It does exhibit some characteristics that are similar to the rare-earth elements (lanthanides), and is often classified as a member of the REE group, along with yttrium. Scandium in oxide form is referred to as scandia, or of course scandium oxide, and the chemical formula is Sc2O3.
