Scandium
transition metalProperties
| Property | Value |
|---|---|
| Atomic Mass | 44.956 amu |
| Category | transition metal |
| Group | 3 |
| Period | 4 |
| Electron Configuration | 1s2 2s2 2p6 3s2 3p6 3d1 4s2 |
| Electronegativity | 1.36 (Pauling) |
| Oxidation States | 3 |
| Melting Point | 1814 K (1540.8 °C) |
| Boiling Point | 3109 K (2835.8 °C) |
| Density | 2.985 g/cm³ |
| Discovered By | Lars Fredrik Nilson (1879) |
About Scandium
Scandium is the lightest transition metal and a beautiful piece of evidence for the periodic table — Mendeleev predicted it as 'eka-boron' in 1871, sketching its atomic mass and oxide formula, and Lars Fredrik Nilson found it in Scandinavian euxenite eight years later with the predicted properties almost intact. Geochemically it's a frustration: it's more abundant in the crust than lead, but it never concentrates into proper ores. It hides at trace levels across hundreds of minerals and is mostly recovered today as a by-product of uranium tailings, bauxite residue, or REE processing. The chemistry is dominated by Sc(III) — small ionic radius, high charge density, behaves a bit like a heavier aluminum. The reason aerospace chemists care is that adding 0.1-0.5% Sc to aluminum forms coherent Al₃Sc precipitates that pin grain boundaries and pin dislocations simultaneously: you get higher strength, better fatigue life, and weldable wrought alloys in the 5xxx and 7xxx series. The Soviet MiG-29 used Al-Sc-Mg alloy for stressed welds; modern interest comes from additive manufacturing where Al-Sc powder prints without hot cracking.
Fun Fact
Scandium was Mendeleev's triumph — he predicted its properties in 1871 as 'eka-boron,' and when Lars Fredrik Nilson discovered it eight years later, its atomic mass, density, and oxide formula matched Mendeleev's predictions almost exactly, convincing many skeptics of the periodic table's validity.
Common Uses
- Al-Sc-Mg alloys for weldable aerospace structures and laser-fused parts
- Metal halide stadium and film-set lamps for high-CRI white light
- Yttria-stabilised zirconia replacement in solid-oxide fuel cell electrolytes
- Sc₂O₃ dopant for high-power laser host crystals
- Lightweight Al-Sc bicycle frames and lacrosse stick shafts
- Radioactive Sc-46 tracer for petroleum reservoir flow studies