Bismuth (Bi)

Bismuth properties

Atomic number

83

Atomic mass

208.98 u

Category

Post-transition metal

Group

15

Period

6

Block

p-block

State at room temp.

Solid

Electronegativity

2.02

Melting point

544.7 K (271.6 °C)

Boiling point

1,837 K (1,563.8 °C)

Density

9.78 g/cm³

Valence electrons

5

Common charges

+3, +5

Oxidation states

+5, +3

Atomic radius

207 pm

Ionization energy

7.289 eV

Electron affinity

0.946 eV

Radioactive

Barely (half-life 2 × 10¹⁹ years)

Discovered

1753

Bismuth electron configuration

The electron configuration of Bismuth (Bi) is [Xe] 4f14 5d10 6s2 6p3. Its 83 electrons are arranged in shells as 2, 8, 18, 32, 18, 5.

Protons, neutrons and electrons in Bismuth

A neutral Bismuth atom has 83 protons and 83 electrons. Most Bismuth atoms have about 126 neutrons: the atomic mass rounded to 209, minus the atomic number 83.

Neutrons are approximate: atoms of the same element can have different numbers of neutrons (isotopes). Atomic number and mass

How many valence electrons does Bismuth have?

5

Bismuth has 5 valence electrons in its outermost shell, shell 6. These are the electrons involved in chemical bonding.

See every element: Periodic table with valence electrons

Bismuth orbital diagram

Each box is an orbital that holds up to two electrons with opposite spins (↑↓). The inner shells are the same as the noble gas in brackets. How to write electron configurations

Molar mass of Bismuth

208.98 g/mol

One mole of Bismuth atoms (6.022 × 10²³ atoms) has a mass of 208.98 grams. Use this value to convert between grams and moles.

Bismuth facts

• Bismuth is technically radioactive, but its half-life is over a billion times the age of the universe.
• Bismuth forms striking rainbow-colored, stair-stepped crystals.
• Bismuth (Bi) has atomic number 83 and is a solid at room temperature. It was discovered in 1753.

Position in the periodic table

Bismuth is element 83, in period 6 and group 15 of the periodic table, in the p-block.

All post-transition metals

Uses of Bismuth

Bismuth is used in place of lead in some solders, fishing weights and ammunition because it is far less toxic. Bismuth subsalicylate is the active ingredient in some common medicines for upset stomach. Bismuth also forms low-melting alloys used in fire sprinkler plugs and safety fuses, and bismuth oxychloride gives a pearly shine to cosmetics.

Who discovered Bismuth?

Bismuth was known in the Middle Ages but was often confused with lead and tin. In 1753 French chemist Claude François Geoffroy showed that it is a distinct element.

Where does the name come from?

Bismuth comes from the German Wismut, an old miners' word of uncertain origin; one suggestion is weiße Masse, 'white mass'. In the 1500s the word was Latinized as bisemutum, which gave the modern name.

Discovery timeline