#75 / 118
75Re186.21
Transition Metalssolid at STPD-block

Rhenium

Group: 7•Period: 6•Standard Atomic Weight: 186.21 u
Open Full Periodic TableView Bohr Model

Why is Rhenium in this position?

Understanding the scientific rationale behind Rhenium's position in the periodic table:

Group Assignment
Group 7

Belongs to Group 7 because it has 7 valence electrons (5d⁵ 6s²).

Period Assignment
Period 6

Belongs to Period 6 because its outermost electrons occupy n=6.

Orbital Block
D-block

Belongs to the d-block because its valence electrons fill 5d orbitals.

Chemical Category
Transition Metals

Classified as a transition metal with record boiling point and high thermal creep resistance.

Atomic Structure & Bohr Shell Model

Shell Distribution: [2, 8, 18, 32, 13, 2]

Bohr Atomic Shell Model(2, 8, 18, 32, 13, 2)

Hover or tap any shell orbit ring to inspect electron counts and 2n² capacities.

75 Protons (p⁺)111 Neutrons (n⁰)
KShell K: Electron 1 of 2Shell K: Electron 2 of 2LShell L: Electron 1 of 8Shell L: Electron 2 of 8Shell L: Electron 3 of 8Shell L: Electron 4 of 8Shell L: Electron 5 of 8Shell L: Electron 6 of 8Shell L: Electron 7 of 8Shell L: Electron 8 of 8MShell M: Electron 1 of 18Shell M: Electron 2 of 18Shell M: Electron 3 of 18Shell M: Electron 4 of 18Shell M: Electron 5 of 18Shell M: Electron 6 of 18Shell M: Electron 7 of 18Shell M: Electron 8 of 18Shell M: Electron 9 of 18Shell M: Electron 10 of 18Shell M: Electron 11 of 18Shell M: Electron 12 of 18Shell M: Electron 13 of 18Shell M: Electron 14 of 18Shell M: Electron 15 of 18Shell M: Electron 16 of 18Shell M: Electron 17 of 18Shell M: Electron 18 of 18NShell N: Electron 1 of 32Shell N: Electron 2 of 32Shell N: Electron 3 of 32Shell N: Electron 4 of 32Shell N: Electron 5 of 32Shell N: Electron 6 of 32Shell N: Electron 7 of 32Shell N: Electron 8 of 32Shell N: Electron 9 of 32Shell N: Electron 10 of 32Shell N: Electron 11 of 32Shell N: Electron 12 of 32Shell N: Electron 13 of 32Shell N: Electron 14 of 32Shell N: Electron 15 of 32Shell N: Electron 16 of 32Shell N: Electron 17 of 32Shell N: Electron 18 of 32Shell N: Electron 19 of 32Shell N: Electron 20 of 32Shell N: Electron 21 of 32Shell N: Electron 22 of 32Shell N: Electron 23 of 32Shell N: Electron 24 of 32Shell N: Electron 25 of 32Shell N: Electron 26 of 32Shell N: Electron 27 of 32Shell N: Electron 28 of 32Shell N: Electron 29 of 32Shell N: Electron 30 of 32Shell N: Electron 31 of 32Shell N: Electron 32 of 32OShell O: Electron 1 of 13Shell O: Electron 2 of 13Shell O: Electron 3 of 13Shell O: Electron 4 of 13Shell O: Electron 5 of 13Shell O: Electron 6 of 13Shell O: Electron 7 of 13Shell O: Electron 8 of 13Shell O: Electron 9 of 13Shell O: Electron 10 of 13Shell O: Electron 11 of 13Shell O: Electron 12 of 13Shell O: Electron 13 of 13PShell P: Electron 1 of 2Shell P: Electron 2 of 2ReZ = 75

Educational Note: This Niels Bohr planetary model visually illustrates principal quantum energy shells ($n=1, 2, 3\dots$) and electron counts. In modern quantum mechanics (Schrödinger model), electrons do not orbit in fixed circular planetary tracks, but exist as 3D probability clouds (orbitals: $s, p, d, f$) governed by the Heisenberg uncertainty principle.

Electron Shell Filling Breakdown

Shell K (n=1):2 / 2 electrons (100%)
Shell L (n=2):8 / 8 electrons (100%)
Shell M (n=3):18 / 18 electrons (100%)
Shell N (n=4):32 / 32 electrons (100%)
Shell O (n=5):13 / 50 electrons (26%)
Shell P (n=6):2 / 72 electrons (3%)
Aufbau Electron Configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d⁵ 6s²

Neutral ground state configuration. Valence electrons: 7.

Atomic & Quantum Properties

Electronegativity (Pauling)1.9 Pauling
1st Ionization Energy760 kJ/mol
Electron Affinity-14 kJ/mol
Atomic Radius (empirical)188 pm
Common Oxidation States+7, +4
Crystal StructureHCP

Physical & Thermal Properties

Density at STP21.02 g/cm³
Melting Point3186 °C (3459 K)
Boiling Point5596 °C (5869 K)
Magnetic OrderingParamagnetic
Discovery Year1925
Discovered ByWalter Noddack, Ida Tacke-Noddack & Otto Berg

Real-World Uses, Occurrence & Compounds

Major Industrial & Everyday Uses
  • Nickel-based single-crystal superalloys for commercial and military jet engine high-pressure turbine blades
  • Platinum-rhenium petroleum catalytic reforming catalysts producing high-octane unleaded gasoline
  • Ultra-high-temperature thermocouples measuring temperatures up to 2200 °C
  • Rocket engine combustion chamber thrusters
Occurrence in Nature

One of the rarest elements in Earth's crust; recovered from flue dusts during the roasting of molybdenite copper ores.

Etymology & Name Origin

From Latin 'Rhenus' meaning the Rhine River in Germany

Important Chemical Compounds
Re₂O₇ (Rhenium heptoxide)
HReO₄ (Perrhenic acid)
ReCl₅ (Rhenium pentachloride)
Interesting Chemical Facts
  • • Rhenium was the very last stable, non-radioactive chemical element ever discovered (in Berlin in 1925).
  • • Over 70% of the world's total rhenium production is consumed by aerospace jet engines to prevent turbine blades from creeping at 1,600 °C.
  • • Rhenium has the highest boiling point of all elements at 5,596 °C—hotter than the surface temperature of the Sun!
Safety & Handling Note

Low toxicity in metallic form; perrhenates irritate mucous membranes.

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