Bromine is the only nonmetal that is liquid at room temperature.
Bromine has the symbol Br and atomic number 35. Under ordinary room conditions, it is a volatile reddish-brown liquid that readily releases a similarly colored vapor. It is one of only two elements that are liquid near room temperature at standard pressure; the other is mercury, which is a metal.
Bromine belongs to the halogen group, alongside fluorine, chlorine, iodine, and astatine. Its melting point is about −7.2 °C and its boiling point is about 58.8 °C, placing normal indoor temperatures between those limits. As the halogens become heavier down the group, their melting and boiling points generally rise, which helps explain why chlorine is a gas while iodine is a solid.
Carl Jacob Löwig first produced bromine in 1825, and Antoine Jérôme Balard independently identified it in 1826. The name comes from the Greek word bromos, meaning stench, referring to its sharp odor. Astatine is not the answer: although it is a halogen, it is normally treated as a solid and is extremely rare and radioactive.