1. The problem statement, all variables and given/known data Assuming that pressure remains constant, at what temperature is the root-mean square speed of a helium atom equal to the root-mean-square speed of an air molecule at STP? Express your answer to 3 significant figures in Kelvin. 3. The attempt at a solution the root mean square speed is given by vrms = Sqrt[3 kT/m] where T is the temperature and m is the mass of one molecule (k is the boltzmann constant) so if we take ratios, we get vrms(He)/vrms(O2) = Sqrt[T(he)/T(O2)] Sqrt[m(O2)/m(He)] I am using oxygen since air is a mixture and there is no such thing as a molecule of air. If you need to compare an ensemble of He atoms to an ensemble of air molecules, use molecular weight = 28.97 so we have vrms(He)/vrms(O2) = Sqrt[T(He)/273][Sqrt[32/4] for vrms(He) = vrms()2), then 1 = (T/273)(8) => T=273/8 solve for T So you get 34.125 C? Then going to Kevlin it would be 307.125 and rounding to 3 significant figures is 307? Is this right??