Element 35

Bromine (Br)

Halogen · Period 4 · Group 17 · p-block

Bromine (Br) is element 35 of the periodic table, a halogen in period 4, group 17 (p-block) with an atomic mass of 79.904 and is a liquid at standard conditions.

At a glance

Atomic number
35
Symbol
Br
Atomic mass
79.904 u
Category
Halogens
Period
4
Group
17
Block
p-block
Phase at STP
liquid

Electron structure

Electron configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p5
Shorthand configuration
[Ar] 3d10 4s2 4p5
Electrons per shell
2, 8, 18, 7
Oxidation states
-1, +1, +3, +4, +5, +7

Physical properties

Melting point
265.8 K
Boiling point
332 K
Density
3.122 g/cm3
Phase
liquid

Atomic properties

Electronegativity (Pauling)
2.96
Atomic radius
94 pm
Covalent radius
120 pm
Van der Waals radius
185 pm
First ionization energy
1140 kJ/mol
Electron affinity
325 kJ/mol

Notable isotopes

IsotopeMassAbundanceStability
Br-7978.9183450.69%Stable

Common uses

  • Flame retardants
  • Pesticides
  • Water purification
  • Photography

Discovery

Year
1826
Discovered by
Antoine Jérôme Balard
Country
France

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