Vanadium at a glance
- Atomic number
- 23
- Symbol
- V
- Atomic mass
- 50.942 u
- Category
- Transition metal
- Group / period
- 5 / 4
- Electron configuration
- [Ar] 3d 3 4s 2
- State at 25 °C
- Solid
- Melting point
- 1910 °C
- Boiling point
- 3407 °C
- Density
- 6.11 g/cm³
- Electronegativity
- 1.63
- 1st ionization energy
- 651 kJ/mol
- Oxidation states
- +5, +4, +3
- Discovered
- 1801
Atomic structure
A neutral vanadium atom has 23 protons and 23 electrons, and its most common isotope carries about 28 neutrons. One atom weighs about 8.46 × 10⁻²⁶ kg, so a mole of vanadium (6.022 × 10²³ atoms) weighs 50.942 g. That nucleus holds 1.22 neutrons for every proton. The electrons fill 4 shells (K 2, L 8, M 11, N 2), which gives the configuration [Ar] 3d 3 4s 2. As a d-block element, both its outer s electrons and its inner d electrons can take part in bonding, which is why it shows more than one oxidation state. It has only one stable isotope, V-51. No other element has a stable isotope with mass number 51, so V-51 has no stable isobars; its neighbours on that line decay into it or away from it.
Physical properties
At room temperature (25 °C) vanadium is a solid. It melts at 1910 °C and boils at 3407 °C, so it stays liquid across a 1497-degree range. It stays solid in molten iron (1538 °C) but would melt in a welding arc. Its density is 6.11 g/cm³, 6.11 times as dense as water. Its atoms have a radius of about 135 pm (Titanium next door is 140 pm). In the solid, its atoms pack into a body-centred cubic lattice.
Chemical behaviour
Its electronegativity is 1.63 on the Pauling scale. Pulling off its outermost electron takes 651 kJ/mol. A bond between vanadium and chlorine would be polar covalent, with an electronegativity difference of 1.5. It releases 51 kJ/mol when it gains an extra electron. Its common oxidation states are +5, +4, +3, so in compounds you will usually meet it as V⁵⁺, V⁴⁺ and V³⁺. Group 5 also holds Niobium, Tantalum and Dubnium, which share its outer-shell pattern.
Where it comes from
It makes up 120 mg/kg of Earth's crust, the 20th most abundant element there. It was first identified in 1801, making it the 34th element to be discovered (counting the 11 known since antiquity together).