Why is a weather balloon never filled completely with He when it is
Q. What would the weather balloon do when it is released?
A. It would rise.
Q. How does the air pressure at high elevations compare with air pressure
at low elevations?
A. Air pressure is lower at high elevations than at low elevations.
Q. What happens to the gas inside a balloon when the air pressure outside
the balloon drops?
A. The gas inside the balloon will expand until its pressure is the same as
the pressure of the air on the outside.
Q. What if the balloon is already full?
A. If the balloon is closed, it will break; if it is open at the bottom,
some of the gas inside will escape, which is a waste.
Richard E. Barrans Jr., Ph.D.
PG Research Foundation, Darien, Illinois
Click here to return to the Environmental and Earth Science Archives
Update: June 2012