Rhenium

TRANSITION METAL · GROUP 7 · PERIOD 6
75
Re
Rhenium
186.21

Atomic Data

Atomic Number75
SymbolRe
Atomic Weight186.21 u
Density (STP)21.02 g/cm³
Melting Point3185.85 °C (3459 K)
Boiling Point5595.85 °C (5869 K)
Electronegativity1.9 (Pauling)
Electron Config.1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d5 6s2
Oxidation States+4, +7
Phase at STPSolid
CategoryTransition Metal
Period / Group6 / 7
CAS Number7440-15-5

Electron Configuration

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[Xe] 4f14 5d5 6s2

Shell n Subshell Electrons Cumulative
K11s22
L22s24
L22p610
M33s212
M33p618
M33d1028
N44s230
N44p636
N44d1046
N44f1460
O55s262
O55p668
O55d573
P66s275
Total 75 75

Isotopes of Rhenium

Rhenium has two naturally occurring stable isotopes. The most abundant is ¹⁸⁷Re, comprising 62.6% of all naturally occurring Rhenium.

Isotope Symbol Protons Neutrons Abundance Stability
Rhenium-185¹⁸⁵Re7511037.4Stable
Rhenium-187¹⁸⁷Re7511262.6Stable

Abundance & Occurrence

Rhenium is present in Earth's crust at approximately 0.0007 ppm by mass and at approximately 0.2 ppm by mass throughout the universe.

Earth's Crust (ppm by mass)

Rhenium
0.0007 ppm
Silicon (ref.)
277,000 ppm
Oxygen (ref.)
461,000 ppm

Universe (ppm by mass)

Rhenium
0.2 ppm
Helium (ref.)
230,000 ppm
Hydrogen (ref.)
739,000 ppm

Discovery & History

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Safety & Handling

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Real-World Uses

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Downloadable Resources

Free periodic table reference sheets for classrooms, study sessions, and laboratory use.

Frequently Asked Questions

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