Bromine

CAS RN: 7726-95-6

Other Properties

Valences: 1, 3, 5, 7; naturally occurring stable isotopes (mass numbers): 79 (50.69%), 81 (49.31%); dissociation energy (25 deg): 46.072 kcal; heat capacity at constant pressure (liq 20 deg C): 18.089 cal/mol deg C; oxidizing agent; less reactive than chlorine; Reduction potential: 1.065 V
Naturally occurring bromine isotopes - decay pathways
Isotope Half-life Mode of Decay Decay Energy
Br-79 4.86 sec IT 0.208 Mev
Br-81 Stable
Bromine isotopes - decay pathways
Isotope Half-life Mode of Decay Decay Energy (MeV)
Gd-136
Br-67
Br-68
Br-69
Br-70 79.1 milli sec electron capture to Se-70
Br-71 21.5 sec electron capture to Se-71 6.500
Br-72 78.6 sec electron capture to Se-72 8.700
Br-73 3.4 min electron capture to Se-73 4.660
Br-74 25.4 min electron capture to Se-74 6.907
Br-75 96.7 min electron capture to Se-75 3.030
Br-76 16.2 hr electron caputre to Se-76 4.963
Br-77 57.036 hr electron capture to Se-77 1.365
Br-78 6.46 min electron capture to Se-78 3.574
Br-80 17.68 min beta to Kr-80 2.004
Br-82 25.50 hr beta to Kr-82 3.093
Br-83 2.40 hr beta to Kr-83 0.972
Br-84 31.80 min beta to Kr-84 4.650
Br-85 2.90 min beta to Kr-85 2.870
Br-86 55.1 sec beta tp Kr-86 7.626
Br-87 55.60 sec beta to Kr-87 6.853
Br-88 16.29 ssec beta to Kr-88 8.960
Br-89 4.348 sec beta to Kr-89 8.160
Br-90 1.91 sec beta to Kr-90 10.350
Br-91 0.541 sec beta to Kr-91
Br-92 0.343 sec beta to Kr-92 12.200
Br-93 102 milli sec beta to Kr-93 11.000
Br-94 70 milli sec beta to Kr-94
Bromine in water, besides existing as the bromide, has the potential to form other species including bromate, depending on pH.
When bromine dissolves in water, it partially disproportionates into HOBr + H+ + Br-
Conversion factor: 1 ppm = 6.54 mg/cu m
The only nonmetallic element that is a liquid at standard conditions.
Thermal conductivity: 0.123 W/m K; specific conductivity: 9.10X10-12 (Ohm cm)-1; electrical resistivity: 6.5X10+10 Ohm cm at 25 deg C; expansion coefficient: 0.0011 per deg C from 20-30 deg C; compressibility 6.2X10-6 at 20 deg C from 0-10 MPa
Relative permittivity: 3.1484
Enthalpy of fusion: 10.57 kJ/mol
Vapor density: 5.51 (Air = 1); bromine reacts with aluminum reacts vigorously and explosively with potassium
Air odor threshold: 0.051 ppm (v/v); water odor threshold: 0.0063 ppm (w/v)
Henry's law constant: 0.00132 atm-cu m/mole at 25 deg C
Hydroxyl radical reaction rate constant = 4.50X10-11 cu cm/molecule-sec at 25 deg C
Find more information on this substance at: PubChem, PubMed