Mobility of rare earth elements, yttrium and scandium from a phosphogypsum stack: Environmental and economic implications.

See more Scandium products. Scandium (atomic symbol: Sc, atomic number: 21) is a Block D, Group 3, Period 4 element with an atomic weight of 44.955912. The number of electrons in each of Scandium's shells is [2, 8, 9, 2] and its electron configuration is [Ar] 3d¹ 4s². The scandium atom has a radius of 162 pm and a Van der Waals radius of 216 pm.Scandium was predicted by Dmitri Mendeleev in 1871 and actually discovered and isolated by Lars Nilson in 1879. One of the transition metals, scandium has a silvery-white appearance in its elemental form which oxidizes to yellow or pinkish upon contact with air. It is occasionally included in the classification of the rare earth elements. Scandium is found in concentrated amounts in the minerals euxenite, gadolinite and thortveitite however, due to the difficulties in the preparation of metallic scandium, global trade of the pure metal is very limited. The origin of the name scandium comes from the Latin word 'scandia' meaning Scandinavia.

See more Yttrium products. Yttrium (atomic symbol: Y, atomic number: 39) is a Block D, Group 3, Period 5 element with an atomic weight of 88.90585. The number of electrons in each of yttrium's shells is [2, 8, 18, 9, 2] and its electron configuration is [Kr] 4d¹ 5s². The yttrium atom has a radius of 180 pm and a Van der Waals radius of 219 pm. Yttrium was discovered by Johann Gadolin in 1794 and first isolated by Carl Gustav Mosander in 1840. In its elemental form, Yttrium has a silvery white metallic appearance. Yttrium has the highest thermodynamic affinity for oxygen of any element. Yttrium is not found in nature as a free element and is almost always found combined with the lanthanides in rare earth minerals. While not part of the rare earth series, it resembles the heavy rare earths which are sometimes referred to as the "yttrics" for this reason. Another unique characteristic derives from its ability to form crystals with useful properties. The name yttrium originated from a Swedish village near Vaxholm called Yttbery where it was discovered.