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?

Maria wants to determine which type of disinfectant kills the most bacteria. which of the following is the best way for maria to determine this? a. ask ten different companies that make disinfectants which type is best. b. put the same amount and species of bacteria on ten identical plates, and add ten different kinds of disinfectant to each plate. c. interview ten different people to determine which type of disinfectant they prefer. d. put the same amount and species of bacteria on ten identical plates, and add a different disinfectant to each plate.

Electrons are extremely important to what area of technology? a) anti-aging research b) household product development c) electronics d) drug discovery

Iron (3) oxide will decompose in the presence of hydrogen gas and heater to produced iron and digydrogen monoxide white a balanced chemical equation