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Plutonium

Element 94 · Actinide

Specimen

Atomic number
94
Atomic mass
[244]
State at room temperature
Solid
Melting point
639.9 °C
Boiling point
3,228 °C
Density
19.84 g/cm³
Discovered
1940

Mass number of the longest-lived isotope, from IUPAC.1 Other physical data from PubChem.2

Can I eat it?

In food and water
Radioactive. Plutonium is radioactive. Its main health effect is cancer of the lung, bone or liver, years after exposure. The levels that most people meet are very low. 3

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The atom

Pu
ShellElectrons
1 (K) 2
2 (L) 8
3 (M) 18
4 (N) 32
5 (O) 24
6 (P) 8
7 (Q) outermost 2
Total94

Configuration [Rn] 5f⁶ 7s²

5f ↑ ↑ ↑ ↑ ↑ ↑
7s ↑ ↓
A shell diagram: each ring is an electron shell and each dot is one electron. The nucleus holds 94 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.

Related elements

Actinides
Ac Actinium Th Thorium Pa Protactinium U Uranium Np Neptunium Am Americium Cm Curium Bk Berkelium Cf Californium Es Einsteinium Fm Fermium Md Mendelevium No Nobelium Lr Lawrencium

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Sources

  1. 1

    IUPAC Commission on Isotopic Abundances and Atomic Weights (CIAAW), 2024. Radioactive Elements .

    Mass number and half-life of the longest-lived isotope of the 34 elements with no standard atomic weight.

  2. 2

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

    Electron configuration, melting and boiling points, density and discovery year for all 118 elements.

  3. 3

    Agency for Toxic Substances and Disease Registry (ATSDR), 2010. Plutonium | ToxFAQs .

    • The main health effect from exposure to plutonium is cancer which may occur years after exposure. The types of cancers you would most likely develop are cancers of the lung, bones, and liver.
    • The levels which most people are exposed are very low and of little health consequence.