Comment on teaching the flux and transport parameters of Maxwellian gas within the kinetic theory

Within the kinetic theory of an ideal gas, the flux of particles having a n umber density n, and average velocity (v) over bar impinging on a plane fro m one side, is sometimes written in textbooks as n (v) over bar /6 and some times as n (v) over bar /4. The validity of each expression is worked out h ere with emphasis on their effect on the pre-factor for the expressions of the transport parameters such as viscosity, diffusion coefficient and heat conductivity. It is shown that n (v) over bar /4 is valid in equilibrium wh ile only when there are gradients, effectively the flux becomes n (v) over bar /6. For the correct derivation of the transport parameters the introduc tion of a distribution function for the collision times or mean free paths is essential. A methodology is suggested on how to teach this subject to un dergraduate and graduate students.