|Name, symbol||Scandium, Sc|
|Scandium in the periodic table|
|Standard atomic weight (Ar)||44.955908(5)|
|Group, block||, d-block|
|Electron configuration||[Ar] 3d1 4s2|
|2, 8, 9, 2|
|Melting point||1814 K (1541 °C, 2806 °F)|
|Boiling point||3109 K (2836 °C, 5136 °F)|
|Density near r.t.||2.985 g/cm3|
|when liquid, at||2.80 g/cm3|
|Heat of fusion||14.1 kJ/mol|
|Heat of||332.7 kJ/mol|
|Molar heat capacity||25.52 J/(mol·K)|
|Oxidation states||3, 2, 1 (an amphoteric oxide)|
|Electronegativity||Pauling scale: 1.36|
1st: 633.1 kJ/mol |
2nd: 1235.0 kJ/mol
3rd: 2388.6 kJ/mol
|Atomic radius||empirical: 162 pm|
|Covalent radius||170±7 pm|
|Van der Waals radius||211 pm|
|Crystal structure||hexagonal close-packed (hcp)|
|Thermal expansion||α, poly: 10.2 µm/(m·K) (at r.t.)|
|Thermal conductivity||15.8 W/(m·K)|
|Electrical resistivity||α, poly: 562 Ω·m (at r.t., calculated)|
|Young's modulus||74.4 GPa|
|Shear modulus||29.1 GPa|
|Bulk modulus||56.6 GPa|
|Brinell hardness||736–1200 MPa|
|CAS Registry Number||7440-20-2|
|Prediction||Dmitri Mendeleev (1871)|
|Discovery and first isolation||Lars Fredrik Nilson (1879)|
Scandium is a chemical element with symbol Sc and atomic number 21. Scandium is classified as a rare earth element, together with yttrium and the lanthanides, due to their similar chemical properties. It is a hard to find element, mainly due to the lack of concentrated ores, with a global production of 10 tonnes per year.
Scandium powder and turnings ignite in air with a brilliant yellow flame to form scandium(III) oxide (also known as scandia).
- 4 Sc + 3 O2 → 2 Sc2O3
Scandium is a silvery-white metal, which slowly oxidizes in air, developing a slight yellow or pinkish cast due to the formation of an oxide layer.
Scandium metal is sold by various chemicals suppliers, though it's quite expensive. Metallium sells a 5 gram sample at $ 97.
Scandium can be extracted by reducing scandium(III) oxide with a more reactive metal, such as calcium. Replacing scandia with scandium(III) fluoride gives the process a better yield.
Another method involves the electrolysis of an eutectic mixture of potassium, lithium, and scandium chlorides, at 700–800 °C. This was the first method used to obtain pure scandium metal.
- Yellow flame
- Make scandium(III) fluoride, an interesting compound which displays negative thermal expansion (shrinks when heated)
- Ellement collecting
Elemental scandium is considered non-toxic, though its compounds display moderate toxicity.
Scandium should be stored in sealed containers or ampoules, away from air, moisture and corrosive vapors.
Due to it's rarity, it's best to try and recycle scandium, instead of throwing it away.