Bismuth

At a glance

Symbol

Bi

Atomic number

83

Average atomic mass

208.98

Group

15

Period

6

Family

post-transition metal

Electron configuration

[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p³

Valence electrons

5

Electronegativity

2.02

Common ions

Bi³⁺

Isotopes

²⁰⁹Bi, long thought stable, is very slightly radioactive: its half-life, measured in 2003, is about 2 × 10¹⁹ years, a billion times the age of the universe

On the table

Period 6, group 15. The other post-transition metals are tinted, and every cell opens its own article.

Electrons and bonding

A metal that gives up its valence electrons to form positive ions, though less readily than the metals to its left.

Properties

State at 25 °C

solid

What it looks like

brittle, silvery-white metal with a pink tint; its crystals shimmer with rainbow colors from a thin oxide layer

Melting point

271.4 °C

Boiling point

1564 °C

Density

9.81 g/cm³

Odd fact

it expands when it freezes, and it is the element most strongly pushed away by a magnet

Where it is found

Rare, and mostly recovered as a byproduct of refining lead, copper and tungsten ores, above all in China.

Discovery and name

Known since the 1400s but often confused with tin and lead, until Claude François Geoffroy showed in 1753 that it was a separate element. The name probably comes from the old German wismuth, perhaps from weisse Masse, white mass.