Neon
No, heavier gas particles diffuse slower than lighter gas particles
Natural gas is lighter than air and rises.
yup
No, all gases are lighter than solids
Helium is the lightest noble gas, so neon, argon, krypton and xenon are all heavier noble gases. Radon's also a noble gas and it's heavier than helium, but it's radioactive so is it really inert?
While it is not a "Noble Gas" it is much lighter than air. It is not lighter than Hydrogen, but it does not ignite as easily.
Some are heavier, but some are lighter. For example, methane rises but propane sinks.
I think it's heavier it hangs around on the bottom
Helium exists as a monatomic gas, with atomic mass of 4.0. Thus any gas with a molecular mass higher than 4.0 would be heavier than helium. Hydrogen is the only gas that is lighter than helium; all others are heavier than helium.
Bottled LPG is heavier than air That why it is recommended to place the gas bottle outside of the cabin. Any gas leaks from the bottle being inside, would collect in the bottom of the boat causing a very explosive mixture
Helium is a gas, so it is not lighter than gas. It is like asking why is water heavier than liquid. Helium is less dense than all other gases except hydrogen, because it has an atomic weight of 4.
helium