Answer: Option (d) is the correct answer.
Explanation:
A molecule or compound which has large molecular mass will be the heaviest in nature.
Since we have to find the heaviest gas out of the given options, so we will calculate the molar mass of each gas as follows.
Molar mass of \(O_{2}\) = 16 g/mol
Molar mass of \(CH{_4}\) = 16.04 g/mol
Molar mass of \(CO_{2}\) = 44.01 g/mol
Molar mass of \(Cl_{2}\) = 70.90 g/mol
Thus, we can conclude that out of the given options \(Cl_{2}\) is the heaviest gas.
