Which is the only non-metal that is liquid at room temperature?

The correct answer is Option (1) → Bromine

Bromine (Br) is the only non-metal that is a liquid at room temperature. It is a halogen, a dark reddish-brown liquid that gives off a choking reddish-brown vapour. Every other non-metal is a gas (oxygen, nitrogen, chlorine) or a solid (carbon, sulphur, iodine).

Mercury is also a liquid at room temperature, but it is a metal, not a non-metal.