Element 51

Antimony (Sb)

Metalloid · Period 5 · Group 15 · p-block

Antimony (Sb) is element 51 of the periodic table, a metalloid in period 5, group 15 (p-block) with an atomic mass of 121.76 and is a solid at standard conditions.

At a glance

Atomic number
51
Symbol
Sb
Atomic mass
121.76 u
Category
Metalloids
Period
5
Group
15
Block
p-block
Phase at STP
solid

Electron structure

Electron configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p3
Shorthand configuration
[Kr] 4d10 5s2 5p3
Electrons per shell
2, 8, 18, 18, 5
Oxidation states
-3, -2, -1, +1, +2, +3, +4, +5

Physical properties

Melting point
903.78 K
Boiling point
1860 K
Density
6.685 g/cm3
Phase
solid

Atomic properties

Electronegativity (Pauling)
2.05
Atomic radius
133 pm
Covalent radius
139 pm
Van der Waals radius
206 pm
First ionization energy
834 kJ/mol
Electron affinity
103 kJ/mol

Notable isotopes

IsotopeMassAbundanceStability
Sb-121120.9038157.21%Stable

Common uses

  • Flame retardants
  • Batteries
  • Alloys
  • Semiconductors

Discovery

Discovered by
Known since antiquity
Country
Unknown

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