Nickel (Ni)

Nickel (symbol Ni) is the chemical element with atomic number 28: a transition metal, solid at 0 °C, with an atomic mass of 58.693 u. Discovered in 1751 (Axel Fredrik Cronstedt).

Nickel is a silvery, corrosion-resistant, magnetic metal. It goes mainly into stainless steel and, increasingly, into electric car batteries. Earth's core contains a significant share of it, as do iron meteorites. It is also the leading cause of contact allergy.

Key facts

Atomic number: 28
Symbol: Ni
French name: Nickel
Atomic mass: 58.693 u
Molar mass: 58.693 g/mol
Family: Transition metals
Position: period 4, group 10, d-block
State at 0 °C: Solid
Melting point: 1,454.9 °C
Boiling point: 2,729.9 °C
Density: 8.91 g/cm³
Electronegativity (Pauling): 1.91
First ionization energy: 737 kJ/mol
Atomic radius: 135 pm
Electron configuration: [Ar] 3d⁸ 4s²
Abundance in Earth's crust: 84 ppm (23rd most abundant element)
Indicative price: 14 $/kg (order of magnitude)
Radioactive: no
Discovery: 1751, Axel Fredrik Cronstedt

Origin of the name

From the German Kupfernickel, “devil's copper.”

What does nickel look like?

A silvery-white metal with a slight golden tinge, shiny, hard and ductile, that keeps its luster in air.

Where is nickel found?

About 85 ppm of Earth's crust, but Earth's core is thought to contain about 5%. Deposits are either sulfides (Canada, Russia) or tropical laterites (Indonesia, Philippines, New Caledonia).

Natural sources

Pentlandite
Garnierite
Nickel laterites
Nickeline

How is nickel produced?

Sulfide ores are concentrated, then smelted; laterites are smelted into ferronickel or dissolved in acid under pressure. Mine production is around 3.5 million tonnes a year, about half of it in Indonesia, where output is booming.

Top producers

Indonesia
Philippines
Russia
New Caledonia (France)
Canada

What is nickel used for?

Stainless steel (about two thirds of consumption).
Lithium-ion battery cathodes (NMC).
Superalloys for turbines and jet engines.
Nickel plating and coatings.
Coins.
Specialty alloys: Invar, shape-memory nitinol.

In everyday life

A stainless steel sink and saucepans
1 and 2 euro coins (rings and centers made of nickel-containing alloys)
Belt buckles and costume jewelry
An electric car battery

Role in living things

Not essential for humans, but vital to many plants and bacteria, where it activates urease, an enzyme that breaks down urea. Some “hyperaccumulator” plants in New Caledonia concentrate several percent of it in their tissues.

Hazards of nickel

Nickel is the most common contact allergen, affecting about 10 to 15% of women in Europe; a European directive therefore limits how much jewelry can release. Dust from some compounds is carcinogenic when inhaled, and nickel tetracarbonyl is an extremely toxic gas.

Cosmic origin

White dwarfs: Produced by the thermonuclear explosion of a white dwarf (type Ia supernova).
Supernovae: Forged in the cores of massive stars, then scattered when they explode.

History of nickel

Saxon miners called a reddish ore that looked like copper but yielded none Kupfernickel, “devil's copper.” In 1751, the Swede Axel Fredrik Cronstedt isolated a new metal from it, which he named nickel. In 1864, engineer Jules Garnier discovered in New Caledonia the ore that bears his name.

Did you know?

Invar, an iron-nickel alloy that barely expands with heat, earned Charles-Édouard Guillaume the 1920 Nobel Prize in Physics, for work done at the International Bureau of Weights and Measures in Sèvres, near Paris.
The American 5-cent coin, nicknamed the nickel, is only 25% nickel; the rest is copper.
Iron meteorites are iron-nickel alloys, fragments of the cores of shattered asteroids.

Isotopes of nickel

Five stable isotopes, nickel-58 being the most common. Radioactive nickel-56 keeps supernovae shining for weeks after they explode.

nickel-56: radioactive, half-life 6.08 days. Made in bulk in supernovae, its decay powers their glow.
nickel-58: 68.077% of natural nickel, stable
nickel-59: radioactive, half-life 76,000 years. Used to date meteorites and estimate the age of sediments on Earth.
nickel-60: 26.223% of natural nickel, stable
nickel-61: 1.14% of natural nickel, stable
nickel-62: 3.635% of natural nickel, stable. The nucleus with the highest binding energy per nucleon of all.
nickel-63: radioactive, half-life 101 years. Electron source in airport explosive detectors and electron capture detectors.
nickel-64: 0.926% of natural nickel, stable. Target for producing medical copper-64.

Related elements

Same family (transition metals): Scandium (Sc), Titanium (Ti), Vanadium (V), Chromium (Cr), Manganese (Mn), Iron (Fe), Cobalt (Co), Copper (Cu), Zinc (Zn), Yttrium (Y), Zirconium (Zr), Niobium (Nb), Molybdenum (Mo), Technetium (Tc), Ruthenium (Ru), Rhodium (Rh), Palladium (Pd), Silver (Ag), Cadmium (Cd), Hafnium (Hf), Tantalum (Ta), Tungsten (W), Rhenium (Re), Osmium (Os), Iridium (Ir), Platinum (Pt), Gold (Au), Mercury (Hg), Rutherfordium (Rf), Dubnium (Db), Seaborgium (Sg), Bohrium (Bh), Hassium (Hs).

Same column (group 10): Palladium (Pd), Platinum (Pt), Darmstadtium (Ds).