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?

Ageochemist examines a piece of metal that he found in the soil. he performs tests to identify the metal from its density, electrical conductivity, and melting point. which statement best describes his investigation? a. he is determining physical properties that are sufficient to identify the metal.b. he is determining chemical properties that are sufficient to identify the metal.c. he is determining physical properties that are insufficient to identify the metal.d. he is determining chemical properties that are insufficient to identify the metal.