4 ms·"heavier than air" air is a mixture of gases - which gas of the mixture are you referring to ?by vbuwivbiu 7y ago"heavier than air" air is a mixture of gases - which gas of the mixture are you referring to ?bqqyz 7y agoA mixture has a density of its own.vbuwivbiu 7y agoand CO2 is part of the mixture which we call 'air' hence the question