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83Bi208.98
Post-Transition Metalssolid at STPP-block

Bismuth

Group: 15•Period: 6•Standard Atomic Weight: 208.98 u
Open Full Periodic TableView Bohr Model

Why is Bismuth in this position?

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

Group Assignment
Group 15

Belongs to Group 15 (Pnictogens) because it has 5 valence electrons (6s² 6p³).

Period Assignment
Period 6

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

Orbital Block
P-block

Belongs to the p-block because its valence electrons occupy 6p orbitals.

Chemical Category
Post-Transition Metals

Classified as a post-transition metal due to its metallic electrical conductivity and dominant +3 inert pair state.

Atomic Structure & Bohr Shell Model

Shell Distribution: [2, 8, 18, 32, 18, 5]

Bohr Atomic Shell Model(2, 8, 18, 32, 18, 5)

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

83 Protons (p⁺)126 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 18Shell O: Electron 2 of 18Shell O: Electron 3 of 18Shell O: Electron 4 of 18Shell O: Electron 5 of 18Shell O: Electron 6 of 18Shell O: Electron 7 of 18Shell O: Electron 8 of 18Shell O: Electron 9 of 18Shell O: Electron 10 of 18Shell O: Electron 11 of 18Shell O: Electron 12 of 18Shell O: Electron 13 of 18Shell O: Electron 14 of 18Shell O: Electron 15 of 18Shell O: Electron 16 of 18Shell O: Electron 17 of 18Shell O: Electron 18 of 18PShell P: Electron 1 of 5Shell P: Electron 2 of 5Shell P: Electron 3 of 5Shell P: Electron 4 of 5Shell P: Electron 5 of 5BiZ = 83

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):18 / 50 electrons (36%)
Shell P (n=6):5 / 72 electrons (7%)
Aufbau Electron Configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 6s² 6p³

Neutral ground state configuration. Valence electrons: 5.

Atomic & Quantum Properties

Electronegativity (Pauling)2.02 Pauling
1st Ionization Energy703 kJ/mol
Electron Affinity-91.2 kJ/mol
Atomic Radius (empirical)143 pm
Common Oxidation States+3, +5
Crystal StructureRhombohedral

Physical & Thermal Properties

Density at STP9.78 g/cm³
Melting Point271.4 °C (544.55 K)
Boiling Point1564 °C (1837 K)
Magnetic OrderingDiamagnetic
Discovery YearAncient
Discovered ByKnown since antiquity; identified as a distinct metal by Claude Geoffroy (1753)

Real-World Uses, Occurrence & Compounds

Major Industrial & Everyday Uses
  • Bismuth subsalicylate (Pepto-Bismol) medicine treating indigestion, nausea, and diarrhea
  • Non-toxic lead-free replacement in fishing sinkers, plumbing fixtures, and shotgun hunting shot
  • Low-melting fusible safety fire-sprinkler plug alloys (Wood's metal / Rose's metal)
  • Thermoelectric cooling Peltier coolers (Bismuth telluride / Bi₂Te₃)
Occurrence in Nature

Mined as bismuthinite (Bi₂S₃) and bismite (Bi₂O₃), and as a byproduct of lead-copper refining.

Etymology & Name Origin

From German 'Wismuth' or 'weiße Masse' meaning white mass

Important Chemical Compounds
Bi₂Te₃ (Bismuth telluride)
C₇H₅BiO₄ (Bismuth subsalicylate / Pepto-Bismol)
BiOCl (Bismuth oxychloride pearlescent cosmetic)
Interesting Chemical Facts
  • • Bismuth forms stunning stepped hopper crystals that shimmer in rainbow iridescent colors due to thin-film light interference on its oxide surface.
  • • Bismuth has the highest diamagnetism of any metal, visibly repelling strong neodymium magnets.
  • • Long thought to be the heaviest stable element, Bismuth-209 was discovered in 2003 to be very slightly radioactive via alpha decay, with a colossal half-life of 20 quintillion years—over a billion times older than the universe!
Safety & Handling Note

Exceptionally non-toxic for a heavy metal; safe for ingestion in medical doses.

Explore Neighborhood Elements

Same Group (Group 15):
#7N#15P#33As#51Sb#115Mc
Same Period (Period 6):
#55Cs#56Ba#57La#58Ce#59Pr#60Nd#61Pm#62Sm#63Eu#64Gd#65Tb#66Dy#67Ho#68Er#69Tm#70Yb#71Lu#72Hf#73Ta#74W#75Re#76Os#77Ir#78Pt#79Au#80Hg#81Tl#82Pb#84Po#85At#86Rn