83
Bi
Bismuth
209
Bismuth (Bi)
Post-Transition MetalGroup 15Period 6p-block-blockRadioactive
Bismuth is a chemical element with symbol Bi and atomic number 83. Bismuth, a pentavalent post-transition metal, chemically resembles arsenic and antimony. Elemental bismuth may occur naturally, although its sulfide and oxide form important commercial ores.
Latin name: Bismuthum
Atomic Number
83
Atomic Mass
209 g/mol
Phase (STP)
Solid
Electron Config.
[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p³
General
SymbolBi
Atomic Number83
Atomic Mass209 g/mol
CategoryPost-Transition Metal
Group15
Period6
Blockp-block
Electron Configuration[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p³
Valence Electrons5
Coloursilvery white
Appearancelustrous silver
CAS NumberCAS7440-69-9
Physical Properties
Phase (STP)Solid
Density9.78 g/cm³
Melting Point271.55°C · 520.79°F · 544.70 K
Boiling Point1563.85°C · 2846.93°F · 1837.00 K
Atomic Properties
Atomic Radius207 pm
Electronegativity2.02 Pauling
Ionization Energy703 kJ/mol
Oxidation States+3, +5, -3
Ion ChargeBi3+/Bi5+
Thermodynamic
Molar Heat25.52 J/(mol·K)
Crystal Structure
Crystal Structurerhombohedral
Mechanical Properties
Mohs Hardness2.25
Nuclear & Hazards
RadioactiveYes
Half-life1.9×10^19 years (Bi-209, effectively stable)
Abundance
In Universe0.00002%
In Sun0.000018%
In Earth's Crust0.0030%
Discovery & History
Discovered Byunknown (first described in 1753 by Claude Geoffroy)
Isotopes of Bismuth
| Isotope | Abundance | Half-life | Decay |
|---|---|---|---|
| Bi-208 | — | 3.68 × 10⁵ years | EC |
| Bi-209 | 100% | 1.9 × 10¹⁹ years | α |
| Bi-210 | — | 5.012 days | β⁻ |