Science 1.5 Explain how pitch and loudness of sound can be varied. Science 2.1 Record and summarize experimental data. Discussion When working with the major gases in our atmosphere, we can't leave out a look at some of our trace gases. Helium is number 2 on the periodic chart with only two protons, which means it is lighter than the air that surrounds it. Students can observe this by playing around with helium-filled balloons.
Blimps also make good examples.
An affect of helium is the change in our voices when we inhale the gas. This change in our voice demonstrates another property of helium. Excluding asthmatic students, inhale helium gas and then speak. Note that the pitch of your voices have suddenly gotten higher. Write a hypothesis with several facts to support it.