51SbAntimony121.7601[Kr] 4d¹⁰ 5s² 5p³
metalloid

Antimony

Antimony is a chemical element with symbol Sb (from Latin:stibium) and atomic number 51. A lustrous gray metalloid, it is found in nature mainly as the sulfide mineral stibnite (Sb2S3). Antimony compounds have been known since ancient times and were used for cosmetics; metallic antimony was also known, but it was erroneously identified as lead upon its discovery.

Electronic structure

A stylized shell model. Electrons are quantum objects, not particles following these literal paths. Sizes and motion are illustrative.

Electrons by shell
Electron configuration
4d10
5s2
5p3

36 is the [Kr] core total across four shells.

Properties

At a glance

Atomic number
51
Atomic mass
121.7601 u
Phase
Solid
Density
6.697 g/cm³
Melting point
903.78 K
Boiling point
1,908 K
First ionization energy
834 kJ/mol
Electronegativity
2.05
Electron affinity
101.059 kJ/mol
Molar heat capacity
25.23 J/(mol·K)
Period
5
Appearance
silvery lustrous gray

Conditions and isotopes affect measured properties. Some properties of short-lived elements are predicted. Electronegativity uses the Pauling scale.

Keep exploring

Explore the stories, imagery, and reference data in more depth. Properties with no value in the reference are marked unavailable.