Other Experimental
Two naturally occurring isotopes: (51)V (99.75%): (50)V (0.25%); the latter is radioactive: Half-life 6X10+15 years;Vanadium metal oxidizes readily above 660 °C;Vanadium is resistant to attack by hydrochloric or dilute sulfuric acid and to alkali solutions. It is also quite resistant to corrosion by seawater but is reactive toward nitric, hydrofluoric, or concentrated sulfuric acids. Galvanic corrosion tests run in simulated seawater indicate that vanadium is anodic with respect to stainless steel and copper but cathodic to aluminum and magnesium. Vanadium exhibits corrosion resistance to liquid metals, (e.g., bismuth and low oxygen sodium).;Vanadium has oxidation states of +2, +3, +4, +5; when heated in air at different temperatures, it oxidizes to a brownish black trioxide, a blue black tetraoxide, or a reddish orange pentoxide. It reacts with chlorine at fairly low temperatures (180 °C) forming vanadium tetrachloride and with carbon and nitrogen at high temperatures forming VC and VN, respectively. The pure metal in massive form is relatively inert toward oxygen, nitrogen, and hydrogen at room temperature.;Crystal structure body-centered cubic; lattice constant, 0.3026 nm; specific heat, 0.50 J/g at 20-100 °C; latent heat of fusion, 16.02 kJ/mol; enthalpy, 5.27 kJ/mol at 25 °C; entropy, 29.5 kJ/mol °C at 25 °C; thermal conductivity, 0.31 W/cm deg K at 100 °C; electrical resistance, 24.8-26.0 microohm cm at 20 °C; magnetic susceptibility 0.11 cu m/mol; superconductivity transition temperature, 5.13 K; recrystallization temperature, 800-1000 °C; modulus of elasticity, (1.2-1.3)X10+5 MPa;Vanadium is ductile and can be forged or rolled at room temperature. ... On prolonged storage it becomes bluish-gray to brownish-black ...;Enthalpy of formation (gas), 514.2 kJ/mol; molar heat capacity at 298.15 K, 24.9 J/ mol K (crystal); 26.0 J/mol K (gas);Enthalpy of fusion, 21.5 kJ/mol at 1910 °C;Not tarnished in air and not appreciably affected by moisture at ordinary temperatures. ...Not attacked by hot or cold hydrochloric acid, by cold sulfuric acid. Reacts with hot sulfuric acid, hydrofluoric acid, nitric acid, aqua regia. Not attacked by bromine water or by aqueous alkalies. Specific heat (20 to 100 °C) 0.12 cal/g/deg C.;Valences = 2, 3, 4, 5; acts as either a metal or a nonmetal and forms a variety of complex compounds ... resistant to corrosion ...;Vanadium has good structural strength and a low fission neutron cross section, making it useful in nuclear applications;Vandium isotopes - decay pathways[Table#2712];Vanadium decay pathways;Table: Naturally Occuring [Table#2713];Vanadium decay pathways;Table: Artificial isotopes [Table#2714]