Vanadium Element Properties

Complete reference for vanadium (V, element 23): atomic data, electron configuration, oxidation states, physical constants, and chemical behavior.

23 V 50.942

Vanadium

Transition Metal — Period 4, Group 5

Atomic Identity

Atomic Number
23
Z
Symbol
V
Standard Atomic Wt.
50.9415 u
IUPAC 2021
Period
4
Group
5
VB
Block
d-block
CAS Number
7440-62-2
V
Discovery
N. G. Sefström
1830
First Isolated
H. E. Roscoe
1867

Electron Configuration

Full notation 1s² 2s² 2p⁶ 3s² 3p⁶ 3d³ 4s²
Noble gas shorthand [Ar] 3d³ 4s²
Electrons per shell 2, 8, 11, 2
Valence electrons 5 (3d³ 4s²)
Unpaired electrons 3 (one per 3d orbital)
Spin multiplicity 4 (quartet, ⁴F₃/₂)
Orbital Diagram (valence)
4s
3d
3 unpaired 3d electrons
Paramagnetic

Three unpaired 3d electrons — follows Hund's rule

Oxidation States in Aqueous Solution

Oxidation State Ion / Species Color Example Compound Notes
+5 VO₂⁺ Yellow V₂O₅ Most stable; dominant in oxidizing conditions
+4 VO²⁺ Blue VOSO₄ Vanadyl ion; stable in mildly reducing conditions
+3 V³⁺ Green VCl₃ Mildly reducing; readily oxidized in air
+2 V²⁺ Violet VSO₄ Strong reducing agent; rapidly oxidized by water and air
+1 V⁺ Rare Exists only in exotic organometallic complexes
0 V Silver Elemental metal; bulk solid or carbonyl V(CO)₆

The sequential color change from yellow (+5) → blue (+4) → green (+3) → violet (+2) is a classic qualitative analysis demonstration in inorganic chemistry labs.

Isotopes of Vanadium

Isotope Symbol Protons Neutrons Mass (u) Abundance Stability
Vanadium-48 ⁴⁸V 23 25 47.9522537 Synthetic Unstable
EC/β⁺ decay, t½ = 15.97 d
Vanadium-49 ⁴⁹V 23 26 48.9485161 Synthetic Unstable
EC decay, t½ = 330 d
Vanadium-50 ⁵⁰V 23 27 49.9471585 0.250% Unstable
Primordial; extremely long-lived, t½ ≈ 1.4×10¹⁷ y
Vanadium-51 ⁵¹V 23 28 50.9439595 99.750% Stable
Stable

Vanadium-51 (⁵¹V) is the dominant stable isotope at 99.750% natural abundance and is the nucleus studied in ⁵¹V NMR spectroscopy. Vanadium-50 is technically radioactive but has such an enormously long half-life that it behaves as a stable isotope in practice.

Physical Properties

State at STP Solid (metal)
Appearance Silvery-gray, lustrous
Density (20 °C) 6.11 g/cm³
Melting Point 1910 °C (2183 K)
Boiling Point 3407 °C (3680 K)
Heat of Fusion 21.5 kJ/mol
Heat of Vaporization 444 kJ/mol
Specific Heat (25 °C) 24.89 J/(mol·K)
Thermal Conductivity 30.7 W/(m·K)
Electrical Resistivity 197 nΩ·m (20 °C)
Hardness (Mohs) 7.0
Crystal Structure Body-centered cubic (bcc)

Chemical Properties

Electronegativity (Pauling) 1.63
Electron Affinity 50.6 kJ/mol
1st Ionization Energy 650.9 kJ/mol
2nd Ionization Energy 1414 kJ/mol
3rd Ionization Energy 2830 kJ/mol
4th Ionization Energy 4507 kJ/mol
5th Ionization Energy 6298.7 kJ/mol
Covalent Radius 153 pm
Ionic Radius (V⁵⁺) 54 pm (6-coord.)
Magnetic Ordering Paramagnetic
Oxidation States +5, +4, +3, +2, +1, 0, −1
Reactivity Corrosion-resistant; attacked by HF and oxidizing acids

Key Facts About Vanadium

Steel Strengthening Agent

About 85% of vanadium produced globally is consumed as ferrovanadium or vanadium pentoxide in steel manufacturing. Adding as little as 0.1% vanadium to steel refines grain structure, dramatically increasing tensile strength, hardness, and wear resistance. Vanadium steel is used in automotive frames, tools, pipelines, and structural rebar.

Vanadium Redox Flow Batteries

Vanadium redox flow batteries (VRFBs) exploit all four oxidation states of vanadium (+2/+3 at the negative electrode and +4/+5 at the positive) to store and release electrical energy. Their long cycle life, scalability, and ability to discharge fully without damage make them attractive for grid-scale renewable energy storage.

Vivid Color Chemistry

Vanadium compounds in aqueous solution display striking colors tied directly to oxidation state: VO₂⁺ (+5) is yellow, VO²⁺ (+4) is blue, V³⁺ is green, and V²⁺ is violet. This sequential color change is a classic inorganic chemistry demonstration and makes vanadium ideal for teaching redox reactions visually.

Contact Process Catalyst

Vanadium(V) oxide (V₂O₅) is the industrial catalyst for the contact process, which converts sulfur dioxide (SO₂) to sulfur trioxide (SO₃) — a key step in manufacturing sulfuric acid, one of the most widely produced chemicals in the world. Vanadium cycles between +5 and +4 oxidation states during catalysis.

Biological Role

Vanadium is an essential trace element for some organisms. Vanadium haloperoxidases in marine algae and fungi use vanadate as a cofactor to catalyze halide oxidation. Some tunicates (sea squirts) accumulate vanadium in their blood cells at concentrations millions of times higher than surrounding seawater, though the biological purpose remains debated.

Named After a Goddess

Vanadium was named by Nils Gabriel Sefström in 1830 after Vanadis, another name for Freya, the Norse goddess of beauty — a tribute to the element's beautifully colored compounds. The name replaced "erythronium," proposed by Andrés del Río, who had first observed the element in 1801 but was persuaded his discovery was merely chromium.

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Summary

Complete reference for vanadium (V, element 23): atomic data, electron configuration, oxidation states, physical constants, and chemical behavior.

How it works

  1. Browse the atomic identity section for symbol, atomic number, and standard atomic weight.
  2. Check the electron configuration panel for full and noble-gas-shorthand notation.
  3. Review the oxidation states table to see the five accessible oxidation states and their characteristic colors.
  4. Consult the physical properties panel for melting point, density, and boiling point.
  5. Use the chemical properties section for electronegativity, ionization energies, and ionic radii.
  6. Click any highlighted value to copy it to your clipboard.

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Last updated: 2026-05-28 · Reviewed by Nham Vu