Nickel

Element 28 · Transition metal

Specimen

Atomic number: 28
Atomic mass: 58.693
State at room temperature: Solid
Melting point: 1,455 °C
Boiling point: 2,913 °C
Density: 8.912 g/cm³
Discovered: 1751

Physical data from PubChem.¹

Can I eat it?

In food and water: Harmful. Nickel is in food and drinking water. In 2020, EFSA set a tolerable daily intake of 13 µg per kg of body weight. EFSA said that current intake may be a concern for infants, toddlers and children. ²

The atom

Shell	Electrons
1 (K)	2
2 (L)	8
3 (M)	16
4 (N) outermost	2
Total	28

Configuration [Ar] 3d⁸ 4s²

3d ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↑

4s ↑ ↓

A shell diagram: each ring is an electron shell and each dot is one electron. The nucleus holds 28 protons. The outermost shell is shown in red. Electrons do not travel on rings: they fill orbitals, regions where an electron is likely to be found. The boxes are those orbitals for the electrons outside the Ar core, with one arrow per electron.

Related elements

Sources

1

National Center for Biotechnology Information (PubChem), 2026. Periodic Table of Elements .

Atomic mass, electron configuration, melting and boiling points, density and discovery year for all 118 elements.
2
European Food Safety Authority (EFSA), 2025. Metals as contaminants in food , Milestones, 2014 (chromium) and 2020 (nickel).
- EFSA updates its scientific advice on the risks to human health from nickel in food and in drinking water ... from 2.8 micrograms per kilogram of body weight to 13 micrograms per kilogram of body weight ... current chronic dietary exposure to nickel may be of concern in young people (infants, toddlers, children)

Specimen

Can I eat it?

The atom

Related elements

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Sources