Helium Balloons

Have you ever wondered why helium balloons stay up in the air?  Well, it’s because helium is a bit lighter  than regular air, which is a mix of oxygen, nitrogen and other gases.

Helium can also change the pitch of our voice. If  a small dose is inhaled  it changes the resonant frequency of the human vocal tract, causing a faster vibration and a higher-pitched, cartoon-character sound.

But be careful, as you never know, if you take in too much helium you may be stuck with a donald duck sounding voice!