Tungsten
Atomic Data
| Atomic Number | 74 |
| Symbol | W |
| Atomic Weight | 183.84 u |
| Density (STP) | 19.25 g/cm³ |
| Melting Point | 3421.85 °C (3695 K) |
| Boiling Point | 5554.85 °C (5828 K) |
| Electronegativity | 2.36 (Pauling) |
| Electron Config. | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d4 6s2 |
| Oxidation States | +2, +3, +4, +5, +6 |
| Phase at STP | Solid |
| Category | Transition Metal |
| Period / Group | 6 / 6 |
| CAS Number | 7440-33-7 |
Electron Configuration
[Xe] 4f14 5d4 6s2
| Shell | n | Subshell | Electrons | Cumulative |
|---|---|---|---|---|
| K | 1 | 1s | 2 | 2 |
| L | 2 | 2s | 2 | 4 |
| L | 2 | 2p | 6 | 10 |
| M | 3 | 3s | 2 | 12 |
| M | 3 | 3p | 6 | 18 |
| M | 3 | 3d | 10 | 28 |
| N | 4 | 4s | 2 | 30 |
| N | 4 | 4p | 6 | 36 |
| N | 4 | 4d | 10 | 46 |
| N | 4 | 4f | 14 | 60 |
| O | 5 | 5s | 2 | 62 |
| O | 5 | 5p | 6 | 68 |
| O | 5 | 5d | 4 | 72 |
| P | 6 | 6s | 2 | 74 |
| Total | 74 | 74 | ||
Isotopes of Tungsten
Tungsten has four naturally occurring stable isotopes. The most abundant is ¹⁸⁴W, comprising 30.64% of all naturally occurring Tungsten.
| Isotope | Symbol | Protons | Neutrons | Abundance | Stability |
|---|---|---|---|---|---|
| Tungsten-182 | ¹⁸²W | 74 | 108 | 26.5 | Stable |
| Tungsten-183 | ¹⁸³W | 74 | 109 | 14.31 | Stable |
| Tungsten-184 | ¹⁸⁴W | 74 | 110 | 30.64 | Stable |
| Tungsten-186 | ¹⁸⁶W | 74 | 112 | 28.43 | Stable |
Abundance & Occurrence
Tungsten is present in Earth's crust at approximately 1.3 ppm by mass and at approximately 0.5 ppm by mass throughout the universe.
Earth's Crust (ppm by mass)
Universe (ppm by mass)
Discovery & History
Read more about the discovery of the periodic table of elements →
Safety & Handling
- Tungsten carbide hard metal disease: Inhalation of tungsten carbide-cobalt (WC-Co) dust causes hard metal lung disease, a serious occupational interstitial pneumonia; the cobalt binder is the primary sensitising agent, but WC amplifies the effect.
- Tungsten trioxide fumes: WO3 fumes produced during high-temperature operations are respiratory irritants; adequate local exhaust ventilation is required at grinding, machining, and sintering operations.
- Dense material hazards: Tungsten's very high density (19.3 g/cm3) makes even small pieces extremely heavy; handle with care to avoid injury from dropping high-density components.
- General toxicity: Tungsten metal has low acute systemic toxicity; it is not classified as a carcinogen in its pure metallic form; occupational hazards arise primarily from compound dusts during manufacturing.
Tungsten in the Real World
Real-World Uses
- Incandescent lamp filaments: Tungsten's uniquely high melting point (3422 °C) and low vapour pressure allow its use as the glowing filament in incandescent and halogen light bulbs, where it reaches ~2800 K without melting.
- Cutting tools (tungsten carbide): Cemented tungsten carbide (WC-Co) is used in drilling bits, milling inserts, turning tips, and wire drawing dies because of its extreme hardness, wear resistance, and hot hardness that maintains performance at machining temperatures.
- X-ray tube anodes: Tungsten anodes in X-ray tubes withstand the intense electron beam impact that generates X-rays; tungsten's high melting point, high atomic number (efficient X-ray production), and good thermal conductivity are all required.
- Kinetic energy penetrators: Tungsten alloy (W-Ni-Fe) rods are used as armour-piercing ammunition in tank and anti-tank cannon, replacing depleted uranium in some nations due to lower radiological concerns.
- TIG welding electrodes: Pure tungsten or lanthanated/thoriated tungsten electrodes carry the electrical current in gas tungsten arc (TIG) welding, maintaining their shape under the intense heat of the welding arc.
- High-temperature components: Tungsten and W-Re alloys are used in rocket nozzle throats, high-temperature furnace heating elements, and vacuum interrupter contacts that carry high currents or operate at extreme temperatures.
Downloadable Resources
Free periodic table reference sheets for classrooms, study sessions, and laboratory use.
Frequently Asked Questions
What is tungsten used for?
Tungsten has the highest melting point of all metals (3422 °C), which drives its key applications. Tungsten carbide (WC) is used in cutting tools, drill bits, and wear-resistant coatings: it is nearly as hard as diamond. Tungsten wire is used in incandescent light bulb filaments. Tungsten is used in welding electrodes (TIG welding), in radiation shielding, and in superalloys for rocket nozzles and jet engines.
Why does tungsten have such a high melting point?
Tungsten's extreme melting point (3422 °C) arises from its exceptionally strong metallic bonds. Tungsten has a half-filled 5d electron shell, giving it 6 bonding electrons per atom: more than any other transition metal. These electrons participate fully in the metallic bond, creating an unusually dense electron cloud binding the tungsten atoms together with extraordinary strength. This same electron configuration gives tungsten its high density and hardness.
How was tungsten discovered?
Tungsten was discovered in 1783 by Spanish chemists Juan José and Fausto Elhuyar, who reduced scheelite (calcium tungstate) with charcoal to obtain the metal. However, Swedish chemist Carl Wilhelm Scheele had identified the oxide 'tungstic acid' in 1781. The name tungsten comes from the Swedish 'tung sten' meaning heavy stone. Its chemical symbol W comes from wolfram, the German name for the mineral wolframite from which it is also extracted.
What is tungsten carbide and why is it so hard?
Tungsten carbide (WC) is a ceramic compound of tungsten and carbon with a hardness second only to diamond and cubic boron nitride. In its practical form, WC powder is mixed with cobalt as a binder and sintered under pressure to make cemented carbide (hard metal). The extremely strong covalent bonds between tungsten and carbon atoms give the material exceptional hardness, wear resistance, and compressive strength, making cemented carbide tools last 10–100 times longer than high-speed steel in machining applications.