Scandium was discovered by Lars Fredik Nilson in 1879. It is a transition element and is widely used as aluminum-scandium alloy for minor aerospace industry.
History and Discovery
The existence of scandium was predicted by Dmitri Mendeleev when he organized the elements in the periodic table. He called it ekaboron (boron like) and suggested some physical and chemical properties in 1869. Lars Fredrik Nilson and his team, in 1879 found this element in the minerals of euxenite and gadolinite. He prepared scandium oxide of high purity. The word scandium has been derived from Latin Scandia meaning Scandinavia . In 1937, metallic scandium was prepared for the first time by Fischer and his colleagues through electrolysis of molten scandium, lithium and potassium chloride.
|Periodic Table Classification||Group 3
|State at 20C||Solid|
|Electron Configuration||[Ar] 3d1 4s2|
|Electron Shell||2, 8, 9, 2|
|Density||2.99 g.cm-3 at 20°C|
|Atomic Mass||44.95 g.mol -1|
|Electronegativity according to Pauling||1.36|
Scandium is the 50th most common element in the earth crust and 35th most abundant element in the Sun. Scandium is found in ores of tin, uranium and tungsten. Thortveitite (Scandium silicate) contain 45% scandium in the form of scandium oxide but it is very rare in nature. Scandium is mostly produced as a by-product during the extraction of uranium through mineral davidite which contain around 0.02% scandium oxide. It is mainly mined in China, Kazakhstan, Madagascar, Norway and Russia.
Scandium is a transition metal. It is silver-white soft metal. When exposed to air it develops a slightly yellowish or pinkish tint. It has a high melting point, but it is as light as aluminum. That means it has relatively low density, about 2.98g/cm3. Its melting point is 1541oC and boiling point is 2836oC. Scandium chemical symbol is Sc. Its atomic number is 21 and atomic weight is 44.95g/mol.
Scandium easily reacts with dilute acids. It is easily burnt and get tarnished in the presence of air. It reacts with water and form hydrogen gas. Pure form of scandium is produced by heating scandium fluoride with calcium metal. Scandium properties are similar with yttrium so it is often classified as a lanthanide like element. Its compound mostly exists in +3 oxidation state. Its oxides and hydroxide are amphoteric (ion that can react with both acid and base). Scandium halides are soluble in water except scandium fluoride which form impermeable passive layer. Organoscandium compounds have lower oxidation states like: 0, +1, +2.
Significance and Uses
- It is used in houses in equipment like color television, fluorescent lamps, energy saving lamps and glasses.
- It is also used to polish glass.
- Aluminum-Scandium alloys are used for aerospace industry.
- Scandium is used in sports equipment like bikes, baseball and bats etc.
- It is also helpful in reducing solidification cracking during welding of high strength aluminum alloys.
- Scandium oxide are used to make high intensity stadium light.
- Scandium iodide is used in mercury vapor lamps.
- Scandium-45 isotope is used in oil refineries.
- Scandium sulfate in diluted form used to improve the germination of seeds like corn, peas and wheat.
Scandium is non-toxic in nature. And is has no known biological role. Certain compounds of scandium, however are highly hazardous for individuals working in laboratory areas and industries. Long term exposure of scandium may cause lungs embolism and liver damage.
Isotopes of Scandium
Naturally scandium is found in 45Sc isotope and it is stable. Thirteen radioactive isotopes have been identified, out of which the most stable one is 46Sc has half-life of 83.8 days, 47Sc has 3.35 days, 44Sc has 4 hours and 48Sc has 43.7 hours .
. Lide, David R. (2004). CRC Handbook of Chemistry and Physics. Boca Raton: CRC Press. pp. 4–28
. Audi, Georges; Bersillon, O.; Blachot, J.; Wapstra, A. H. (2003). “The NUBASE Evaluation of Nuclear and Decay Properties”. Nuclear Physics A. Atomic Mass Data Center. 729: 3–128.