Br
79.904Bromine
Brom
Bromine is a reddish-brown liquid halogen with atomic number 35. It is the only liquid nonmetal at room temperature and is known for bromide chemistry, flame retardants, silver bromide photography and organic bromination reactions.
35
79.904 g/mol
[Ar] 3d¹⁰ 4s² 4p⁵
2 | 8 | 18 | 7
2.96
3.122 g/cm³
-7.35 °C
58.85 °C
Antoine Jérôme Balard
Bromine was discovered independently by Carl Jacob Löwig and Antoine-Jérôme Balard in the 1820s. Its name comes from the Greek bromos, meaning stench, because bromine has a strong irritating odor.
Bromine-79
Natural abundance: About 50.7%. Stable isotope of bromine.Bromine-81
Natural abundance: About 49.3%. Stable isotope of bromine; nearly equal abundance creates a characteristic mass spectrum pattern.HBr
Hydrogen BromideStrong acid in water and reagent in organic synthesis.AgBr
Silver BromideLight-sensitive compound historically central to photographic film.NaBr
Sodium BromideBromide salt used in photography, drilling fluids and chemical synthesis.NBS
N-BromosuccinimideOrganic brominating reagent used in radical and allylic bromination.CH₃Br
Methyl BromideHistorical fumigant largely restricted because of ozone-depletion concerns.- Brominated flame retardants in plastics and textiles, with restrictions on some persistent compounds
- Silver bromide in traditional photographic film and paper
- Water treatment and pool chemistry using bromine-releasing compounds
- Organic synthesis, including bromination reactions
- Some pharmaceuticals, dyes and specialty chemicals
Bromide may have specialized biological roles in some organisms and connective-tissue chemistry, but bromine is not usually treated as a major essential nutrient for humans.
- Bromine is the only nonmetal that is liquid at room temperature.
- The two main bromine isotopes have nearly equal abundance, giving brominated molecules a distinctive M and M+2 mass spectrum pattern.
- Silver bromide made film photography possible because it darkens through light-sensitive chemistry.
- Bromine vapor is corrosive and hazardous, so elemental bromine requires careful handling.
- Bromine has atomic number 35 and belongs to group 17, the halogens.
- Its electron configuration is [Ar] 3d¹⁰ 4s² 4p⁵.
- Bromine commonly forms Br⁻ in bromide salts.
- Halogen reactivity generally decreases down the group from fluorine to iodine, so bromine is less reactive than chlorine but more reactive than iodine.
What is the atomic number of bromine?
The atomic number of bromine is 35.
What is the electron configuration of bromine?
Bromine has the electron configuration [Ar] 3d¹⁰ 4s² 4p⁵.
Is bromine a liquid at room temperature?
Yes. Bromine is the only nonmetal that is liquid at room temperature.
What is bromine used for?
Bromine is used in flame retardants, photography chemistry, water treatment, organic synthesis, dyes and pharmaceuticals.
Why is silver bromide used in photography?
Silver bromide is light-sensitive, so it can record images in traditional photographic film and paper.
Why do bromine compounds show an M and M+2 mass spectrum pattern?
Bromine-79 and bromine-81 occur in nearly equal abundance, producing two molecular-ion peaks about two mass units apart.