Sulfur Hexafluoride

[basilone0331]

Helium is about 6 times lighter than air and that is what causes the high pitch. Sulfur hexafluoride is about 6 times heavier than air...


http://www.youtube.com/watch?v=Z_zF2WFUi7k


http://www.youtube.com/watch?v=d-XbjFn3aqE&