Bromine

Bromine - Br

CAS: 7726-95-6
Description: Heavy, red-brown, fuming liquid with a choking, irritating odor
Classification: Halogen
Date of Discovery: 1826
Discoverer: Antoine J. Balard
Name Origin: Greek brômos, "stench"

Atomic Number: 35
Number of Neutrons: 45
Atomic Mass: 79.904(1) amu
Melting Point: -7.2 °C
Boiling Point: 58.78 °C
Density (293 K): 3.12 g/cm³ (liquid)
7.59 g/l (gas)
Atomic volume: 23.5 cm³/mol
Electrical resistivity:
Thermal conductivity: 0.00122 W/cmK
Enthalpy of atomization: 111.71 kJ/mol
Enthalpy of vaporization: 15.438 kJ/mol
Enthalpy of fusion: 5.286 kJ/mol
Specific heat capacity: 0.473 J/gK

Energy levels: 2-8-18-7
Electron configuration: [Ar]3d¹⁰4s²4p⁵
Crystal Structure: Orthorhombic
Atomic radius: 1.12 Å
Covalent radius: 1.14 Å
Oxidation States: -1, +1, +3, +5, or +7
Electronegativity, Pauling: 2.96
Electron affinity: 3.363590 eV
First ionization energy: 11.814 eV
2nd ionization energy: 21.8 eV
3rd ionization energy: 36.0 eV
Polarizability: 3.05 10^-24cm³

Isotope	Natural Abundance	Atomic Mass	Half-life	Decay Mode	Spin
⁶⁹Br	68.9499	⁺
⁷⁰Br	69.9442	0.08 s	⁺
⁷¹Br	70.9393	21 s	⁺
⁷²Br	71.9365	1.31 m	⁺	3
⁷³Br	72.9318	3.4 m	⁺	3/2-
^74mBr	46 m	⁺	4-
⁷⁴Br	73.92989	25,4 m	⁺
⁷⁵Br	74.92578	1.62 m	⁺	3/2-
^76mBr	1.4 s	IT	4+
⁷⁶Br	75.92454	16.0 h	⁺	1-
^77mBr	4.3 m	IT	9/2+
⁷⁷Br	76.921380	2.376 d	EC	3/2-
⁷⁸Br	77.921146	6.45 m	⁺; EC	1+
^79mBr	4.86 s	IT	9/2+
⁷⁹Br	50.69(7)	78.918338	Stable	3/2-
^80mBr	4.42 h	IT	5-
⁸⁰Br	79.918530	17.66 m	^-; EC; ⁺	1+
⁸¹Br	49.31(7)	80.916291	Stable	3/2-
^82mBr	6.1 m	IT; ^-	2-
⁸²Br	81.916805	1.471 d	^-	5-
⁸³Br	82.915181	2.40 h	^-	3/2-
^84mBr	6.0 m	^-	(6-)
⁸⁴Br	83.91651	31.8 m	^-	2-
⁸⁵Br	84.91561	2.87 m	^-	/2-
⁸⁶Br	85.91880	55.5 s	^-	2-
⁸⁷Br	86.92072	55.6 s	^-; n	3/2-
⁸⁸Br	87.92407	16.3 s	^-; n	1-
⁸⁹Br	88.92640	4.35 s	^-; n	3/2-
⁹⁰Br	89.9306	1.91 s	^-; n	2-
⁹¹Br	90.9339	0.54 s	^-; ^-, n
⁹²Br	91.9392	0.31 s	^-; ^-, n
⁹³Br	92.9431	0.10 s	^-, n
⁹⁴Br	0.07 s	^-, n
Discovered by Balard in 1826, but not prepared in quantity until 1860. A member of the halogen group of elements, it is obtained from natural brines from wells in Michigan and Arkansas. Little bromine is extracted today from seawater, which contains only about 85 ppm. Bromine is the only liquid nonmetallic element. It is a heavy, mobile, reddish-brown liquid, volatilizing readily at room temperature to a red vapor with a strong disagreeable odor, resembling chlorine, and having a very irritating effect on the eyes and throat; it is readily soluble in water or carbon disulfide, forming a red solution, is less active than chlorine but more so than iodine; it unites readily with many elements and has a bleaching action; when spilled on the skin it produces painful sores. It presents a serious health hazard, and maximum safety precautions should be taken when handling it. Much of the bromine output in the U.S. was used in the production of ethylene dibromide, a lead scavenger used in making gasoline antiknock compounds. Lead in gasoline, however, has been drastically reduced, due to environmental considerations. This will greatly affect future production of bromine. Bromine is also used in making fumigants, flameproofing agents, water purification compounds, dyes, medicinals, sanitizers, inorganic bromides for photography, etc. Organic bromides are also important. Natural bromine is made of two isotopes, ⁷⁹Br and ⁸¹Br. Thirty-three isotopes and isomers are known. LINKS: Addition of bromine to hydrocarbons Bromine Chemistry Bromine Science & Environmental Forum Dead Sea Bromine Group Reaction of Aluminum and Bromine Return Sources for the information on this website include: Lide, David R., ed. CRC Handbook of Chemistry and Physics, 78th Ed., 1997-1998.

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