Preferred Label : mean free path;
Detailed label : mean free path, λ;
IUPAC definition : The average distance a molecule travels between collisions. For a molecule, λ (
2 π n d m 2 )-1, where n is the number of molecules per unit volume and dm is their
mean diameter. For O sub 2 /sub at one atmosphere and 25 C, this distance is only
9.7 x 10E-6 cm; at 10E-6 atmospheres and 25 C it is 9.7 cm. For an aerosol particle,
the mean free path, λ B in the Stokes region (see Stokes law) is given by: λ B 3
k T m m B where m is the mass of the particle, k is the Boltzmann constant (1.381
x 10E-23 J K-1), T is the temperature (K) and B is the mobility.;
Origin ID : M03778;
See also
The average distance a molecule travels between collisions. For a molecule, λ (
2 π n d m 2 )-1, where n is the number of molecules per unit volume and dm is their
mean diameter. For O sub 2 /sub at one atmosphere and 25 C, this distance is only
9.7 x 10E-6 cm; at 10E-6 atmospheres and 25 C it is 9.7 cm. For an aerosol particle,
the mean free path, λ B in the Stokes region (see Stokes law) is given by: λ B 3
k T m m B where m is the mass of the particle, k is the Boltzmann constant (1.381
x 10E-23 J K-1), T is the temperature (K) and B is the mobility.
