Quick Facts
| Property | Value |
|---|---|
| Symbol | Ni |
| Atomic Number | 28 |
| Atomic Mass | 58.693 u |
| Category | Transition Metal |
| Period | 4 |
| Group | 10 |
| Block | d |
| Electron Configuration | [Ar] 3d⁸ 4s² |
Physical Properties
| Property | Value |
|---|---|
| State at 20°C | Solid |
| Density | 8.908 g/cm³ |
| Melting Point | 1455°C (1728 K) |
| Boiling Point | 2913°C (3186 K) |
| Appearance | Lustrous, silvery-white metal |
Atomic Properties
| Property | Value |
|---|---|
| Electron Configuration | [Ar] 3d⁸ 4s² |
| Electronegativity | 1.91 (Pauling scale) |
| First Ionization Energy | 737.1 kJ/mol |
| Atomic Radius | 124 pm |
| Covalent Radius | 124 pm |
| Van der Waals Radius | 163 pm |
History and Discovery
Discovered by: Axel Fredrik Cronstedt Year of Discovery: 1751 Location: Stockholm, Sweden
Etymology
The name "nickel" comes from German "Kupfernickel" (copper demon or false copper), a term miners used for nicolite ore that looked like copper but yielded none.
Discovery Story
Axel Fredrik Cronstedt discovered nickel in 1751 while studying kupfernickel ore. Miners had long cursed this ore because it looked like copper but was worthless to them. Cronstedt isolated a new metal from it, which he named after the ore. Nickel had actually been used unknowingly in alloys for millennia.
Isotopes
| Isotope | Natural Abundance | Half-life | Decay Mode |
|---|---|---|---|
| ⁵⁸Ni | 68.08% | Stable | - |
| ⁶⁰Ni | 26.22% | Stable | - |
| ⁶¹Ni | 1.14% | Stable | - |
| ⁶²Ni | 3.63% | Stable | - |
| ⁶⁴Ni | 0.93% | Stable | - |
Occurrence
Natural Abundance
Nickel is the 22nd most abundant element in Earth's crust (84 ppm). It is much more abundant in Earth's core. Major ores are pentlandite ((Ni,Fe)₉S₈) and limonite (nickel-bearing laterites). Major producers are Indonesia, Philippines, Russia, and Australia.
Extraction and Production
- Sulfide Ores: Roasting and refining (Sudbury, Russia)
- Laterite Ores: High-pressure acid leach or pyrometallurgical processes
- Sources: Nickel mining worldwide
- Global production: about 2.5 million tons annually
Applications and Uses
Stainless Steel
- Primary use (about 65% of production)
- 300-series stainless steels contain 8-10% nickel
- Kitchen appliances and utensils
- Medical equipment
Alloys
- Superalloys for jet engines
- Nichrome (heating elements)
- Monel (marine applications)
- Cupronickel (coins)
Plating
- Decorative nickel plating
- Corrosion protection
- Undercoat for chrome plating
Batteries
- Nickel-metal hydride (NiMH) batteries
- Nickel-cadmium batteries
- Electric vehicle battery components
Biological Role
Nickel is essential for some bacteria, plants, and animals but its role in humans is unclear.
In the Human Body
- About 10 mg in adult body
- Not established as essential for humans
- Some nickel-containing enzymes exist in bacteria
- May influence iron absorption
Dietary Sources
Chocolate, nuts, legumes, and grains contain nickel.
Safety and Hazards
Toxicity
Nickel compounds, especially nickel carbonyl (Ni(CO)₄), are highly toxic and carcinogenic. Nickel causes contact dermatitis in sensitive individuals.
Handling Precautions
- Nickel carbonyl is extremely toxic—exposure can be fatal
- Skin contact can cause nickel allergy
- Nickel dust is a respiratory hazard
- Classified as possibly carcinogenic to humans (Group 2B)
Environmental Impact
Nickel mining can cause significant local pollution. Nickel in soil and water affects plant and aquatic life.
Interesting Facts
- The US five-cent "nickel" coin is actually 75% copper and only 25% nickel
- Nickel is one of only four elements that are ferromagnetic at room temperature
- Nickel-62 has the highest binding energy per nucleon of any nuclide
- Ancient Chinese used nickel in coins called "white copper" without knowing it
- About 9% of people are allergic to nickel