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Rhenium

Element 75 · Transition metal

Specimen

Atomic number
75
Atomic mass
186.21
State at room temperature
Solid
Melting point
3,186 °C
Boiling point
5,596 °C
Density
20.8 g/cm³
Discovered
1925

Atomic mass from IUPAC.1 Other physical data from PubChem.2

Can I eat it?

In food and water
Not needed, little harm known. Rhenium is one of the rarest metals on Earth. The body does not use it. There are few studies of its toxicity, so this verdict rests on weak evidence. 3

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The atom

Re
ShellElectrons
1 (K) 2
2 (L) 8
3 (M) 18
4 (N) 32
5 (O) 13
6 (P) outermost 2
Total75

Configuration [Xe] 4f¹⁴ 5d⁵ 6s²

4f ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓ ↑ ↓
5d ↑ ↑ ↑ ↑ ↑
6s ↑ ↓
A shell diagram: each ring is an electron shell and each dot is one electron. The nucleus holds 75 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 Xe core, with one arrow per electron.

Related elements

Group 7
Mn Manganese Tc Technetium Bh Bohrium

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Sources

  1. 1

    IUPAC Commission on Isotopic Abundances and Atomic Weights (CIAAW), 2024. Abridged Standard Atomic Weights 2024 .

    The atomic mass shown for the 84 elements that have a 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

    Royal Society of Chemistry, Periodic Table, 2026. Rhenium - Element information, properties and uses .

    Reference page; its Biological role and Natural abundance sections are quoted.

    • Rhenium has no known biological role. Natural abundance Rhenium is among the rarest metals on Earth.
  4. 4

    National Institute of Standards and Technology (NIST), 2026. Atomic Weights and Isotopic Compositions for All Elements .

    Isotopic composition of each element; the most abundant isotope sets the neutron count in the nucleus view.