In the absence of turbulent mixing, the partial pressure of each constituent of air would fall off with height above sea level in Earth's atmosphere as Pi=P0ie−Migz/RT where Pi is the partial pressure at the height z, P0i is the partial pressure of component i at sea level, g is the acceleration of gravity, R is the gas constant, T is the absolute temperature, and Mi is the molecular mass of the gas. As a result of turbulent mixing, the composition of Earth's atmosphere is constant below an altitude of 100 km, but the total pressure decreases with altitude as P=P0e−Mavegz/RT where Mave is the mean molecular weight of air. At sea level, xN2= 0.78084 and xHe= 0.00000524 and T= 300. K. Im not really sure where to start with this. I figured maybe just start with the exponent of e and im confused right off the bat. using the info give it would be e^(28.9 g mol-1)(9.81m s-2)(6500m)/(300k)(R).....so im not sure what R to use, also i sort of remember something about e not being able to be raised to something with units and i end up with all kinds of units left all over the place?