What property of gas molecule affects the speed at which it diffuses?

Helium and Ethlyene Oxide. Your answer is MASS.

Explanation:

Diffusion is faster at higher temperatures because the gas molecules have greater kinetic energy. effusion refers to the movement of gas particles through a small hole. Graham's law state's that the effusion rate of a gas is inversely proportional to the square root of the mass of its particles.

the number of valence electrons for each molecule or ion is shown beneath the structure. remember hydrogen will not have more than two electrons. this hydrogen is part of a covalent bond (sharing two electrons). a double bond here would cause hydrogen to share four electrons with phosphorus.