On an as yet undiscovered planet, the atmo-
sphere is composed of a mixture of 79% argon
and 20% oxygen (volume percentage) along
with trace amounts of other gases, including
CO2, Kr, and Ne. An enterprising student on
that planet wishes to sell the equivalent of he-
lium balloons to small children. Heliun is not
available.
Which of the gases
1) krypton
II) carbon dioxide
III) methane
IV) propane
V) nitrogen
VI) carbon monoxide
would be an acceptable replacement so that
the balloons will float in that atmosphere?