At standard temperature and pressure (STP), carbon is a solid, so it would be denser than air at STP.
Some are heavier, but some are lighter. For example, methane rises but propane sinks.
Because, carbon dioxide is heavier than air whereas helium is lighter than air.
Just, simply, Lighter than Air Vehicles are lighter than air, so that makes them fly, and Heavier than air vehicles are heavier than air, but they use airfoils on the wings to fly.
Helium is lighter than air
No, carbon dioxide is heavier than helium. Carbon dioxide has a molecular weight of about 44 g/mol, while helium has a molecular weight of 4 g/mol. This means that helium is lighter than carbon dioxide and will rise above it in the presence of air.
Nitrous Oxide is heavier than air.
One is lighter and the other one is heavier. :D
hydrogen
No, it is heavier than air and will sink to the floor.
Helium is typically used to make balloons fly up in the air because it is lighter than air and creates lift. Hydrogen is also lighter than air and can be used, but it is flammable. Carbon dioxide is heavier than air and would cause a balloon to sink.
they are heavier than air hence why they don't fly unless in motion.
one is lither