Do siphons work for gasses? There are videos of sulfur hexafluoride which show it is so dense (6.17 kg/m^3), an aluminum foil boat will float on it like water. I'm curious if gasses can be used in a siphon. 
I'm particularly interested because there's a lot of heavy argon (1.65 kg/m^3) & mostly radon (9.73 kg/m^3) coming from the ground in my FL apartment complex, as well as a series of retention ponds with tubular drains. My lease included a waiver agreeing not to lay on the grass or put my head within a foot of the ground. 
I'd like to know if gasses in general can function in a siphon, but it's interesting to consider radon & argon potentially siphoning around in Florida. 
(Something like the many ponds near where I live)

 A: As long as the outlet tube has greater vertical depth than the inlet tube, the weight of falling gas in the outlet tube should maintain an area of decreased pressure at the top of the siphon which should keep the gas in the inlet tube from sliding back into the source pool, and a flow should be maintained. I don't see why this wouldn't work. The Wikipedia article explains the theory behind this. Under ordinary atmospheric pressure, iquid tensile strength within the siphon should not be necessary to maintain flow.
This paper by Ramette and Ramette describes a working carbon dioxide siphon.  The authors showed by experiment that intermolecular forces are not necessary to maintain the flow.  The molecular weight of argon is about 40, radon 222.  The molecular weight of carbon dioxide is 44, and the molecular weight of air is about 29.  You should be able to siphon argon and radon.  The intake pipe should reach to the bottom of the source, as argon will float on top of radon, and the heavier gas should siphon with less chance of interruption.
Ramette and Ramette found three conditions necessary for a siphon to work: (1) The fluid or gas being siphoned must be more dense than the ambient atmosphere, (2) gravity, and (3) ambient atmospheric pressure must be greater than internal pressure inside the top of the siphon, in order to prevent gravity from pulling the fluid or gas in the shorter intake tube back down to the source.
