The radius of an air molecule is approximately 1.8 x 101" to, its mass is about 4.8 x 1W3\" kg and it has 5 degrees of freedom. The molecular weight of air is 29 and its density is 1.29 kg m'il under standard conditions. 4.1 a Estimate the values of the coefcient of viscosity 1}, the thermal conductivity 2n and the diffusion coefcient D under these conditions. 4.2 In Check that for ain A U D i ~1 and '\" e 1 arch. I} Also, check that the quantities are indeed dimensionless. 11-19 (a) 1.10 x 10 5Pas. 7.39 x 10 ' Jm 's K '. 8.53 x 10-6 m's