Balloons!
Gaseous Helium is easily compressed and is stable, (as opposed to Hydrogen). It is lighter than surrounding air.
helium balloons
You can use air but it won't float so I would recommend helium. If you suck in helium, it will make your voice sound weird.... Try it!!
helium is used for excitation of neon atoms in helium neon laser..
Inhale
the use for balloons mostly
Liquid helium is used to cool the superconducting electromagnets.
Helium
its the 2nd element on the periodic table and it makes things lighter, such as helium balloons, which float as helium is lighter than air
helium is used to cool superconducting magnets in mri scanners as helium is lighter then air airships use them as gasses
Humidified helium replaced oxygen to prevent further erosion
Helium is less dense than air, and therefore the balloon will float.
Helium is used to reaplce hydrogen on a n airplane because it is nonflammable