Which set of gases is listed from lowest to highest root-mean-square speed at 25 $\circ$ C?

Question

Quizplus · Accepted Answer

The root-mean-square speed of a gas is proportional to the square root of its temperature and inversely proportional to the square root of its molar mass. At the same temperature, the molar mass of the gases increases in the order Kr < CO2 < NO2 < SF6. Therefore, the root-mean-square speed of the gases decreases in the order SF6 < Kr < NO2 < CO2.

Which Set of Gases Is Listed from Lowest to Highest ∘\circ∘

Which Set of Gases Is Listed from Lowest to Highest $\circ$