Bismuth (Bi)
Element 83 · Post-transition metal · Solid at 25 °C · Group 15, Period 6
Bismuth is the heaviest element with an effectively stable isotope. It grows striking rainbow-colored “hopper” crystals, melts at low temperature in safety alloys, and soothes stomachs in bismuth subsalicylate.
On the periodic table, bismuth sits in group 15 — the pnictogens (nitrogen group) — in period 6. It is one of 12 elements classified as a post-transition metal, and at room temperature (25 °C) it is a solid.
The post-transition metals sit between the transition metals and the metalloids. They are genuine metals — shiny and conductive — but softer, weaker, and lower-melting than the d-block metals, and their chemistry has more covalent character. Everyday examples from this family include aluminium foil, tin cans, and lead batteries.
Properties of bismuth
| Atomic number (Z) | 83 |
|---|---|
| Symbol | Bi |
| Atomic mass | 208.98 |
| Category | Post-transition metal |
| Group | 15 |
| Period | 6 |
| Block | p-block |
| Metal / nonmetal | Metal |
| State at 25 °C | Solid |
| Electron configuration | [Xe] 4f14 5d10 6s2 6p3 |
| Electronegativity (Pauling) | 2.02 |
| Melting point | 271.4 °C (544.55 K / 520.52 °F) |
| Boiling point | 1,564 °C (1,837.15 K / 2,847.2 °F) |
| Density | 9.78 g/cm³ |
Position in the periodic table
Bismuth shares group 15 — the pnictogens (nitrogen group) with Nitrogen (N), Phosphorus (P), Arsenic (As), Antimony (Sb), Moscovium (Mc). Elements in the same group have the same number of outer electrons, so they tend to behave alike chemically — comparing them is one of the fastest ways to see periodic trends in action.
Physical properties
Bismuth melts at 271.4 °C (544.55 K / 520.52 °F) and boils at 1,564 °C (1,837.15 K / 2,847.2 °F), giving it a liquid range of about 1,292.6 °C at standard pressure.
Its density is 9.78 g/cm³.
See also: the interactive periodic table, how to read the periodic table, metals, nonmetals & metalloids.