4E10.20: HELIUM BALLOON ON LIQUID NITROGEN

PURPOSE: To show that helium gas contracts when it is cooled.

DESCRIPTION: A helium balloon which is cooled by a liquid nitrogen bath becomes heavier than air. When the balloon is removed from the liquid nitrogen it warms up, expands, and floats away.

SUGGESTIONS:

REFERENCES:

EQUIPMENT: Helium balloon, liquid nitrogen.

SETUP TIME: 5 min.


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