Uranium

Element 92 · Actinide

Specimen

Atomic number
92
Atomic mass
238.029
State at room temperature
Solid
Melting point
1,135 °C
Boiling point
4,131 °C
Density
18.95 g/cm³
Discovered
1789

Physical data from PubChem.1

Can I eat it?

In food and water
Radioactive. All uranium is radioactive, but natural uranium in water and food harms the kidneys as a chemical. ATSDR says its health effects come from chemistry, not radiation. Soluble compounds harm at lower doses. 2

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The atom

U
ShellElectrons
1 (K) 2
2 (L) 8
3 (M) 18
4 (N) 32
5 (O) 21
6 (P) 9
7 (Q) outermost 2
Total92

Configuration [Rn] 5f³ 6d¹ 7s²

5f ↑ ↑ ↑
6d ↑
7s ↑ ↓
A shell diagram: each ring is an electron shell and each dot is one electron. The nucleus holds 92 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 Rn core, with one arrow per electron.

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Sources

  1. 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. 2

    Agency for Toxic Substances and Disease Registry (ATSDR), 2013. Uranium | ToxFAQs .

    • Kidney damage has been seen in humans and animals after inhaling or ingesting uranium compounds.
    • Health effects of natural and depleted uranium are due to chemical effects and not to radiation.
    • Ingesting water-soluble uranium compounds will result in kidney effects at lower doses than following exposure to insoluble uranium compounds.