helium
Hydrogen was, and is, the lightest gas
Hydrogen is the lightest gas.
Yes it is, and it's also the lightest gas in the universe.
gas is the lightest in weight
helium is the lightest air
generally, you can look at the Periodic Table of Elements. hydrogen is the lightest of both
Hydrogen is the lightest gas found in air.
Hydrogen gas has the lightest density of any liquid.
the lightest gas is hydrogen
hydrogen
Helium
no, the lightest liquid has a lot more density than the heaviest gas.