The mass percentage is 15.1465%.
The density of an object or quantity of matter is its mass divided by its volume.
I don’t actually know for sure, but I think it would sink. Most of the mass of the molecule is from the oxygen.
Amu of O2 = 32
Amu of C = 12
And since most of the balloon is oxygen, it has no reason to actually float. It would be denser than the air, I’d imagine. I could be totally wrong here, I’m guessing based on my knowledge of chemistry
Diffusion is a process that results from the random motion of molecules and results in a net movement of matter from a high-concentration region to a low-concentration zone.