51 Sb 121.76

Antimony

metalloid

Properties

Atomic number
51
Atomic mass
121.76 u
Category
metalloid
Group
15
Period
5
Block
p-block
State (room temp)
Solid
Outer-shell electrons
5
Electronegativity
2.05 (Pauling)
Density
6.697 g/cm³
Melting point
630.63 °C
Boiling point
1634.85 °C

Electron configuration

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p³

Noble-gas shorthand: [Kr] 4d¹⁰ 5s² 5p³

Electrons per shell: 2, 8, 18, 18, 5 — that's 5 in the outermost shell.

See how electron configuration is built →

Sb
Bohr model — outer-shell electrons in blue

About 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.

Position in the periodic table

Open the interactive periodic table →

Data compiled from Wikipedia, PubChem, and IUPAC. Source.