Hydrogen, helium, ammonia, methane, neon, coal gas and pure nitrogen are all lighter than air. A pocket of air can be made lighter than the surrounding air by heating it. Continue Reading.
Related Questions. 1  Do 2015 Jeep Wrangler Sports have back air vents 1 answer I recently bought a 2015 Jeep Wrangler Sport and I am not sure if it has back air vents or not... If it does I can't seem to find them.
1 A non-vented fuel cap is recommended when your fuel tank is ventilated through the filler neck. 2  A vented fuel cap is equipped with a special breathing valve so that it can be used on non-ventilated fuel tanks.