Answer :
Since chlorine and argon are propellant and sulfur is solid. Then the answer is 2) Bromine.
Answer: Option (2) is the correct answer.
Explanation:
STP means standard temperature and pressure.
At STP chlorine exists as a gas, sulfur exists as a solid and argon also exists as a gas.
Whereas bromine exists as a liquid at STP.
Thus, we can conclude that out of the given options bromine is the element which exists as a liquid at STP.
