Bromine

Symbol: Br
Atomic number: 35
Category: halogens
Group: 17
Period: 4
Block: p
Atomic weight: 79.904 g/mol
Electrons per shell: 2, 8, 18, 7
CAS number: 7726-95-6
Phase: liquid
Density: 3.1028 kg/dm³ (near room temperature)
Melting point: 265.8 K (-7.2 °C, 19 °F)
Boiling point: 332.0 K (58.8 °C, 137.8 °F)
Crystal structure: orthorhombic
Oxidation states: 5, 4, 3, 1, -1
Electronegativity: 2.96 (Pauling scale)
Name's origin: bromos
Name's meaning: a Greek word which means 'the stench of he-goats' due to the characteristic smell of the vapors
Facts:
- is a reddish-brown volatile liquid at standard room temperature that is intermediate in reactivity between chlorine and iodine
- bromine vapours are corrosive and toxic
- the main applications for bromine are in fire retardants and fine chemicals
- has no known role in human health, but organobromine compounds do occur naturally
- is toxic and causes burns
- as an oxidizing agent, it is incompatible with most organic and inorganic compounds
- reacts vigorously with metals, especially in the presence of water, as well as most organic compounds, especially upon illumination
- exists exclusively as bromide salts in diffuse amounts in crustal rock