Bromine

General:

Name:Bromine Symbol:Br
Type: Halogen Atomic weight:79.904
Density @ 293 K:3.122 g/cm3 Atomic volume:23.5 cm3/mol
Discovered:

Bromine was discovered by A.J. Balard in 1826 in Montpellier, France. The name comes from the Greek word "bromos" meaning "stench".

States

State (s, l, g):liquid
Melting point:277 K (-7 °C) Boiling point:332 K (58.9 °C)

Energies

Specific heat capacity:0.473 J g-1 K-1 Heat of atomization:112 kJ mol-1
Heat of fusion:10.57 kJ mol-1 of Br2 Heat of vaporization :29.96 kJ mol-1 of Br2
1st ionization energy:1139.9 kJ mol-1 2nd ionization energy:2103.4 kJ mol-1
3rd ionization energy:3473.4 kJ mol-1 Electron affinity:324.7 kJ mol-1

Oxidation & Electrons

Shells:2,8,18,7 Electron configuration: [Ar] 3d10 4s2 4p5
Minimum oxidation number: -1 Maximum oxidation number:7
Min. common oxidation no.: -1 Max. common oxidation no.:5
Electronegativity (Pauling Scale):2.96 Polarizability volume:3.1 Å3

Appearance & Characteristics

Structure:layers of Br2 Color:red-brown
Hardness:mohs
Harmful effects:

Bromine is poisonous and causes skin burns.

Characteristics:

Pure bromine is diatomic, Br2.

Bromine is the only nonmetallic element that is liquid at ordinary temperatures.

It is a dense, reddish-brown liquid which evaporates easily at room temperature to a red vapor with a strong, chlorine-like odor.

Bromine is less reactive than chlorine or fluorine but more reactive than iodine. It forms compounds with many elements and, like chlorine, acts as a bleaching agent.


Uses:

Bromine compounds are used as pesticides, dyestuffs, water purification compounds, and as a flame-retardants in plastics.

1,2-dibromoethane is used as an anti-knock agent to raise the octane number of gasoline and allow engines to run more smoothly. This application has declined as a result of environmental legislation.

Potassium bromide is used as a source of bromide ions for the manufacture of silver bromide for photographic film.

Reactions

Reaction with air:none Reaction with 6 M HCl:none, dissolves Br2(aq)
Reaction with 15 M HNO3: Reaction with 6 M NaOH:mild, ⇒ OBr-, Br-

Compounds

Oxide(s):Br2O, BrO2 Chloride(s): BrCl
Hydride(s):HBr

Radius

Atomic radius:115 pm Ionic radius (1+ ion):pm
Ionic radius (2+ ion):pm Ionic radius (3+ ion):pm
Ionic radius (2- ion):pm Ionic radius (1- ion):182 pm

Conductivity

Thermal conductivity:0.12 W m-1 K-1 Electrical conductivity:1.0 x 10-10 S m-1

Abundance & Isotopes

Abundance earth's crust:2.4 parts per million, 0.6 by moles
Abundance solar system:parts per billion by weight, parts per billion by moles
Cost, pure: $5 per 100g
Cost, bulk:$0.15 per 100g
Source:

Bromine is obtained from natural brine deposits. Some bromine is still extracted today from seawater, which contains only about 70 ppm.

Isotopes:

26 whose half-lives are known, with mass numbers 68 to 94. Of these, only two are stable: 79Br and 81Br.

Other

Other:

 

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