A balloon filled with helium rises when you let it go. A balloon filled with carbon dioxide sinks. Explain the difference

Question

anonymous · Answer

helium has less mass than oxygen and carbon dioxide has more

pooja195 · Answer

molar mass of air ~ 32x21% + 28x78% = 28.56
molar mass of helium =4
molar mass of carbon dioxide = 12+16x2 = 44
You can see that molar mass <molar mass of air <molar mass of carbon dioxide ...
So, balloon filled with helium rises, while balloon filled with carbon dioxide sinks

jfraser · Answer

it's not an issue of "mass", but of density. Objects will float or sink depending on the densities of the object and the fluid they are placed in. He is less dense than air, CO2 is more dense than air