Which set of gases is listed from fastest to slowest effusion rate?

Question

Quizplus · Accepted Answer

The effusion rate of a gas is directly proportional to the speed of its particles. NO has the lightest particle among all the given gases and therefore has the highest effusion rate. N₂O and NO₂ have the same particle size, but N₂O has more particles, which makes it slightly slower than NO₂. N₂O₄ has the heaviest particle and therefore has the slowest effusion rate. Therefore, the gases listed from fastest to slowest effusion rate is NO > N₂O > NO₂ > N₂O₄, which is option B.

Which Set of Gases Is Listed from Fastest to Slowest