Bromine 

Bromine is a chemical element of the halogen family, symbol Br and atomic number 35. Other halogens are fluorine, chlorine, iodine and astatine. Its name derives from the Greek word "bromos" (stench) due to its pungent odor.

Physical properties :

• Ordinary liquid state (non-magnetic)
• Melting point 7.2°C
• Boiling point 58.8°C
• Energy of fusion 5.286 kJ-mol-1
• Energy of vaporization 29.96 kJ-mol-1 (1 atm, 58.8°C); 30.91 kJ-mol-1 (1 atm, 25°C)
• Molar volume 19.78 10-3 m3-mol-1
• Vapor pressure 5,800 Pa at 6.95°C
• Sound velocity 206 m-s-1at 20 °C

Chemical properties :

• Density 3.102 g/ml at 20°C
• Solubility in water 35.00 g/l at 20°C
• Vapor density (air=1): 5.5

Use :

• Flame retardants: Bromine is used in flame retardants for plastics and textiles, as it can slow the spread of fire.
• Medicines: In medicine, it is used in certain radiotracers used in positron emission tomography (PET scan).
• Photography: Historically, bromine was used in the manufacture of photographic paper.
• Oil drilling: Bromine is used in oil drilling fluids to regulate pressure and prevent the formation of toxic gases.
• Chemical reagents: Used as a reagent in organic chemistry.
• Water treatment: Sometimes used in water treatment as a disinfectant.
• Scientific Research: Used in certain scientific research experiments.