Nickel
Element 28 · Transition Metal
Nickel is a hard, silvery-white transition metal prized for resisting corrosion and holding a polish. Discovered in 1751, its name comes from kupfernickel, German for devil's copper, after an ore that looked like copper but yielded none. Alloyed with chromium it becomes stainless steel; plated onto other metals it gives a bright, durable finish.
Nickel is also one of the few metals that is ferromagnetic at room temperature, alongside iron and cobalt. Its compounds are common contact allergens, which is why nickel-free jewelry exists.
Key facts
| Atomic number | 28 |
|---|---|
| Atomic weight | 58.693 |
| Category | Transition Metal |
| Group / Period | 10 / 4 |
| Block | d |
| Electron configuration | [Ar] 3d8 4s2 |
| Common oxidation states | +2, +3 |
| State at STP | Solid |
| Electronegativity | 1.91 |
| Atomic radius | 149 pm |
| Density | 8.908 g/cm³ |
| Melting point | 1455 °C |
| Boiling point | 2913 °C |
Occurrence
Nickel is mined from sulfide ores such as pentlandite and from laterite deposits in tropical regions. It is far more abundant deep underground — Earth's core is largely an iron-nickel alloy, delivered by the same kind of meteorites that occasionally reach the surface.
Applications
Stainless steel typically contains 8-10% nickel for corrosion resistance
Coins in many countries are nickel-plated or nickel alloys
Nickel-cadmium and nickel-metal-hydride batteries power tools and hybrids
Electroplating deposits nickel for a hard, shiny, protective coating
Raney nickel catalyzes hydrogenation in food and chemical industries
Common compounds
- nickel oxide
- nickel sulfate
- nickel chloride
- nickel carbonyl
The US five-cent 'nickel' coin is actually 75% copper and only 25% nickel.
Data source: IUPAC standard atomic weights 2021