Question: A balloon is filled with Helium, and then is opened and pressed up to someone's mouth to make a voice high, why does it do this?
Choices:
text: gas fills the new area
label: A
text: gas easily is dispersed
label: B
text: gas moves around freely
label: C
text: gas is lighter than air
label: D
Answer: A
Fact: when a gas in an open container evaporates, that gas spreads out into the air