Periodic table › Bismuth
1. Identity and classification
Soft, ductile, silvery-white metallic solid with relatively low melting point compared to d-block transition metals
- Name and symbol
- Bismuth (Bismuth) · Bi
- Atomic number
- 83
- Relative atomic weight / mass number
- 208.98 ± 0.01
- Group · period · block
- 15 · 6 · p
- Category
- Post-transition Metal
- State near room temperature
- Solid
- Stable isotopes
- No stable isotopes
- CAS number
- 7440-69-9
Square brackets [A] indicate a representative isotope mass number, not an average atomic weight. Neutron counts differ between isotopes.
2. Atomic structure and electron configuration
- Protons · electrons in a neutral atom
- 83 · 83
- Neutrons in reference isotope
- 126 (209Bi)
- Full electron configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹⁴ 5d¹⁰ 6s² 6p³- Abbreviated configuration
[Xe]6s² 4f¹⁴ 5d¹⁰ 6p³- Electrons per shell
- 2, 8, 18, 32, 18, 5
- Listed oxidation states
- +5, +3
- Electronegativity
- 2.02 (Pauling)
- First ionization energy
- 703.282 kJ/mol · 7.289 eV
- Electron affinity
- 91.275 kJ/mol
- Covalent radius
- 148 pm
- van der Waals radius
- 207 pm
Configurations of superheavy elements may include theoretical predictions. Different definitions of atomic radius are not interchangeable.
3. Physical and thermal properties
- Density
- 9.807 g/cm³
- Melting point
- 544.55 K · 271.4 °C · 520.52 °F
- Boiling point
- 1837 K · 1563.85 °C · 2846.93 °F
- Crystal structure
- Rhombohedral
- Specific heat
- 0.122 J/(g·K)
- Thermal conductivity
- 7.97 W/(m·K)
- Enthalpy of fusion
- 11.3 kJ/mol
- Enthalpy of vaporization
- 151 kJ/mol
- Magnetic ordering
- Diamagnetic
- Mohs hardness
- 2.25
- Speed of sound
- 1790 m/s
Density and structure depend on temperature, pressure and allotrope. 25°C is a room-temperature reference, not STP. Unestablished values are not zero.
4. Chemical behavior and compounds
The listed electron configuration and oxidation states describe atomic structure; compound properties depend on bonding and composition.
Selected compounds: BiO / Bi₂O₃ (Oxide) · BiClₙ (Chloride) · BiFₙ (Fluoride)
Reaction reference
Oxidation behavior depends on temperature, surface passivation and the chemical environment.
Direct reaction with water is element- and condition-dependent.
5. Isotopes
| Isotope | Status | Natural abundance | Half-life |
|---|---|---|---|
| 209Bi | Radioactive | 100% | 2.01E19 Y |
Half-life units: s seconds, m minutes, h hours, d days, Y years. A dash means no natural-abundance value is given, not zero. Listed records are selected ground states; metastable states are distinct.
6. Discovery and occurrence
- Discovery
- 1753 CE
- Scientists associated with discovery
- Known to alchemists; confirmed by Claude François Geoffroy (1753)
- Location
- Europe / South America
- Origin
- Natural
- Listed crustal abundance
- Not established
Minerals and naming reference
Bismuthinite (Bi₂S₃), Bismite (Bi₂O₃), byproduct of Pb/Cu refining
Named from scientific/historical roots associated with Bismuth (Bi), discovered or characterized by Known to alchemists; confirmed by Claude François Geoffroy (1753).
7. Applications
Bismuth subsalicylate stomach medicine (Pepto-Bismol), non-toxic replacement for lead in solder, plumbing, and fishing sinkers, hopper crystals
Detailed applications by field
- everyday
- Bismuth subsalicylate stomach medicine (Pepto-Bismol), non-toxic replacement for lead in solder, plumbing, and fishing sinkers, hopper crystals
- industry
- Used in post-transition metal processing, specialized alloys, and chemical manufacturing (Bismuth subsalicylate stomach medicine (Pepto-Bismol), non-toxic replacement for lead in solder, plumbing, and fishing sinkers, hopper crystals).
- electronics
- Applied in electronic components, semiconductors, or functional coatings where Bismuth's electronic structure ([Xe] 4f¹⁴ 5d¹⁰ 6s² 6p³) provides target conductivity.
- medicine
- Restricted to controlled nuclear medicine or fundamental radiochemical research.
- energy
- Utilized in power generation, battery materials, catalysts, or nuclear technology involving Bismuth.
- aerospace
- High-performance materials, structural alloys, or space instrumentation utilizing Bismuth.
- agriculture
- Not used in agriculture due to radioactivity or heavy-metal toxicity.
- science
- Spectroscopic standard, crystallography, and quantum chemistry studies of Period 6 p-block elements.
8. Biological role and safety
Hazard depends on the isotope, chemical form, dose and exposure route.
Elemental substances, ions, compounds and radioisotopes can have different health effects. This is an educational reference; laboratory work requires the material safety data sheet and trained supervision.
Biological role reference
Classified as non-essential in human and biological systems.