Science Wiki

Bismuth is a chemical element on the periodic table with the atomic symbol Bi, atomic number 83, and standard atomic weight 208.98 u. Classified as a Post-Transition within Group 15 and Period 6 (p-block), bismuth possesses a ground-state electron configuration of [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p³ distributed across 6 concentric Bohr electron shells (2 · 8 · 18 · 32 · 18 · 5) with 5 outer-shell electrons. Diamagnetic metal that forms iridescent stair-stepped hopper crystals and expands on freezing. Long considered stable until 2003, when ²⁰⁹Bi was shown to alpha-decay with a half-life of 2.01 × 10¹⁹ years—over a billion times the age of the universe!

⚛️ Interactive Periodic Table Lab: Explore Bismuth (Bi, Z = 83) in the CRV Science Dynamic Periodic Table & Bohr Orbital Lab to visualize its animated 2 · 8 · 18 · 32 · 18 · 5 electron shells, simulate live phase transitions from 0 K to 6,000 K, and compare periodic heatmaps across all 118 IUPAC elements.

Electron Shell Architecture and Ground-State Configuration

A neutral atom of bismuth contains 83 protons in its atomic nucleus balanced by 83 electrons occupying quantized atomic orbitals. In the Bohr-Sommerfeld and quantum-mechanical orbital models, these electrons populate 6 principal energy shells (K (n=1): 2e⁻, L (n=2): 8e⁻, M (n=3): 18e⁻, N (n=4): 32e⁻, O (n=5): 18e⁻, P (n=6): 5e⁻), terminating in the directional dumbbell-shaped p-orbital (azimuthal quantum number l = 1) with ground-state configuration [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p³. Removing the most loosely bound valence electron from an isolated gaseous bismuth atom requires a first ionization energy of 703 kJ/mol, while its tendency to attract shared bonding electrons is quantified by a Pauling electronegativity of 2.02.

Periodic Table Position and Neighboring Elements

Within the periodic table, Bismuth occupies Period 6, Group 15 of the p-block (Post-Transition Metals). Along Period 6, it is flanked by Lead (Pb, Z = 82) and Polonium (Po, Z = 84). Vertically within its periodic family, Bismuth shares valence orbital symmetry and homologous chemical trends with Moscovium (Mc). Learners can interactively compare Bismuth's orbital radii, ionization energy, and Pauling electronegativity against all neighboring elements in the Dynamic Periodic Table Lab.

Standard Phase, Melting Point, and Boiling Point Dynamics

At standard ambient temperature and pressure (298.15 K / 25 °C, 1 atm), elemental bismuth exists as a crystalline solid. As thermal energy increases, its crystal or molecular lattice undergoes solid-to-liquid fusion at a melting point of 544.7 K (+271.55 °C / +520.8 °F) and transitions to the vapor phase at a normal boiling point of 1,837 K (+1563.85 °C / +2846.9 °F), spanning a liquid thermodynamic range of 1292.30 K. In the CRV Science Dynamic Periodic Table, dragging the live temperature slider between absolute zero (0 K) and solar-photosphere temperatures (6,000 K) dynamically tracks Bismuth's state transitions in real time alongside enthalpy and entropy phase equilibria.

Quantitative Atomic and Thermodynamic Parameter Matrix

Characteristic Oxidation States and Coordination Chemistry

As a p-block post-transition metal situated to the right of the d-block, its valence electrons experience incomplete nuclear shielding from filled d (and in Period 6–7, f) subshells, resulting in higher electronegativity, softer metallic lattices, and the relativistic inert-pair effect. In chemical compounds, bismuth exhibits characteristic oxidation states of +3, +5. Depending on the electronegativity difference (Δχ) of its bonding partners—such as Oxygen (χ = 3.44), Fluorine (χ = 3.98), Chlorine (χ = 3.16), Nitrogen (χ = 3.04), Carbon (χ = 2.55), or Hydrogen (χ = 2.20)—bismuth forms redox-specific oxides, halides, hydrides, or coordination complexes governed by Gibbs free energy (ΔG = ΔH − TΔS).

Nucleosynthesis, Discovery History, and Elemental Origins

First identified or isolated in 1753, Bismuth carries a distinct cosmological and geochemical signature. With atomic number Z = 83 beyond the iron-56 binding-energy peak, bismuth is synthesized astrophysically via neutron-capture nucleosynthesis—combining slow neutron capture (the s-process in asymptotic giant branch stars) and rapid neutron capture (the r-process in neutron-star mergers and core-collapse supernovae).

Biochemical Classification: Abiotic / Technological / Synthetic

In comparative biochemistry and systems physiology, Bismuth is classified as Abiotic / Technological / Synthetic. No known essential biological role; important in planetary geochemistry, astrophysics, materials science, or nuclear physics. Across terrestrial and marine ecosystems, its chemical speciation interacts with thermodynamics, enthalpy, entropy, chemistry.

Key Mechanistic Functions and Technological Uses

Diamagnetic metal that forms iridescent stair-stepped hopper crystals and expands on freezing. Long considered stable until 2003, when ²⁰⁹Bi was shown to alpha-decay with a half-life of 2.01 × 10¹⁹ years—over a billion times the age of the universe! Researchers and students can further investigate Bismuth's functional role alongside all 118 elements by launching the Interactive Periodic Table & Element Detective Lab on CRV Science Learn.

What is the electron configuration and valence shell structure of Bismuth (Bi)?

Bismuth (atomic number Z = 83) has the ground-state electron configuration [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p³, distributing its 83 electrons across 6 shells as 2 · 8 · 18 · 32 · 18 · 5. Its outermost shell contains 5 electrons, placing Bismuth in Group 15, Period 6 (p-block) as a member of the Post-Transition Metals. You can watch these 83 electrons orbit the nucleus in real time in the Dynamic Periodic Table Bohr Lab.

What phase of matter is Bismuth at room temperature, and when does it melt or boil?

At standard room temperature (298 K / 25 °C) and 1 atm pressure, Bismuth is a crystalline solid. It melts at 544.7 K (+271.55 °C / +520.8 °F) and boils at 1,837 K (+1563.85 °C / +2846.9 °F). Using the 0–6,000 K temperature slider in the Interactive Periodic Table, you can observe Bismuth's exact solid, liquid, and gas transitions relative to all other elements.

How does Bismuth function in biochemistry, materials science, and technology?

Diamagnetic metal that forms iridescent stair-stepped hopper crystals and expands on freezing. Long considered stable until 2003, when ²⁰⁹Bi was shown to alpha-decay with a half-life of 2.01 × 10¹⁹ years—over a billion times the age of the universe! In biological systems, it is categorized under Abiotic / Technological / Synthetic, with principal oxidation states of +3, +5 and a first ionization energy of 703 kJ/mol.