Vanadium
transition metalProperties
| Property | Value |
|---|---|
| Atomic Mass | 50.942 amu |
| Category | transition metal |
| Group | 5 |
| Period | 4 |
| Electron Configuration | 1s2 2s2 2p6 3s2 3p6 3d3 4s2 |
| Electronegativity | 1.63 (Pauling) |
| Oxidation States | 5, 4, 3, 2 |
| Melting Point | 2183 K (1909.8 °C) |
| Boiling Point | 3680 K (3406.8 °C) |
| Density | 6.11 g/cm³ |
| Discovered By | Andres Manuel del Rio (1801) |
About Vanadium
Vanadium is the textbook demonstration metal for variable oxidation states — drop a strip of zinc into ammonium metavanadate solution and you watch the color shift from yellow VO₂⁺ through blue VO²⁺ and green V³⁺ down to violet V²⁺ as zinc reduces it stepwise. Sefström rediscovered it in 1830 in Swedish iron ore (del Rio's 1801 find had been dismissed as impure chromium) and named it for Vanadís, the Norse goddess, on account of those colors. Industrial vanadium goes almost entirely into ferrovanadium for high-strength low-alloy steels — even 0.1 wt% V refines the grain structure of steel rebar and pipeline plate enough to bump yield strength noticeably. The catalysis side runs on V₂O₅: it's the active oxide in the contact process for sulfuric acid, where it oxidizes SO₂ to SO₃ at around 450 °C with a turnover that platinum can match but at 1/100th the cost. The vanadium redox flow battery exploits the same multi-state behavior — V²⁺/V³⁺ on one side, VO²⁺/VO₂⁺ on the other, separated by a proton-exchange membrane.
Fun Fact
Sea squirts (ascidians) concentrate vanadium in specialized blood cells called vanadocytes at up to a million times the surrounding seawater concentration — and nobody is entirely sure why.
Common Uses
- Ferrovanadium additive in high-strength low-alloy structural steels
- V₂O₅ catalyst for SO₂ oxidation in the contact process
- Ti-6Al-4V titanium alloy for jet engine compressor blades and implants
- Vanadium redox flow batteries for grid-scale renewable storage
- Maleic anhydride catalyst (vanadyl phosphate) from n-butane oxidation
- EPR spin probes using vanadyl complexes in coordination chemistry