1. Helium was the cause of the Hindenburg explosion. (True or False)
2. In 1915, helium cost $2500 per cubic foot. How much did it cost in 1940 (per cubic foot)?
3. Inhaled helium causes your vocal cords to constrict, giving you a voice much higher in pitch. (True or False)
4. In order of abundance in the universe, where is helium ranked among elements?
5. What does helium mean?