Scandium, Sc

Scandium is a chemical element that has the symbol Sc and atomic number 21. A silvery white metal that is always present as compounds, scandium ores occur as rare minerals from Scandinavia and elsewhere, and it is sometimes considered along with yttrium, and the lanthanides and actinides, to be a rare earth element.

Scandium is a rare, hard, silvery, rough very dark metallic element that develops a slightly yellowish or pinkish cast when exposed to air. It is not resistant to weathering when pure and is destroyed on prolonged contact with most dilute acids. However, like some other reactive metals, this metal is not attacked by a 1:1 mixture of nitric acid (HNO3) and hydrofluoric acid, HF.

The rarity of scandium is not an arbitrary fact. The thermonuclear reactions that produce the elements in this range of atomic numbers tend to produce much greater quantities of elements with an even atomic number. These elements were usually produced by the fusion of lighter elements with helium-4 nuclei, starting with carbon-12 (element six). Thus, the common elements in the range of scandium are atomic numbers 18 (argon), 20 (calcium), 22 (titanium), and 24 (chromium); with elements with odd atomic numbers 19 (potassium), 21 (scandium), and 23 (vanadium) being rarely produced, and thus much less common. The production of the odd-numbered elements in this range result from much less common thermonuclear reactions, as is explained elsewhere.

Technical Data
Symbol Sc Density (20°C)/gcm-3 3
Atomic number 21 Melting point /°C 1539
No. of naturally occurring isotopes 1 Boiling point /°C 2748
Atomic weight 44.9559 ΔHfus/kJmol-1 15.77
Electronic configuration [Ar]3d14s2 ΔHvap/kJmol-1 332.71
Metal radius(12-coordinate)/pm 162 ΔHf(monoatomic gas)/kJmol-1 376(+/-20)
Ionic radius(6-coordinate)/pm 74.5 Ionization energy/kJmol-1 I 631
E° (M3+(aq)\ + 3e- →M(s))/V -2.077 Ionization energy/kJmol-1 II 1235
Electronegativity χ 1.3 Ionization energy/kJmol-1 III 2389
Electrical resistivity (20°C)/μohm cm 50-61  
Evaporation Techniques
Temperature (oC) @Vap. Pressure Techniques Remarks
10-8 Torr 10-6 Torr 10-4 Torr Electron Beam Crucible Coil Boat
714 837 1002 Excellent Al2O3 - Tungsten Alloys with Tantalum

Evaporation Materials
S2-5000-M pieces 12mm and smaller
S2-5001-M Ingot (Please ask for sizes)

The foils are available in either rectangular or circular shape. Please enter width and length or diameter of the required foil.

S2-3003-F 0.004" (0.1mm)
S2-3007-F 0.008" (0.2mm)
S2-2000-R 0.250" (6.35mm)
S2-2001-R 0.500" (12.7mm)
S2-4001-S 0.015" (0.38mm)
S2-4002-S 0.020" (0.5mm)
S2-4003-S 0.030" (0.76mm)
S2-4004-S 0.040" (1mm)