If the mean free path fer a given molecule is `1.1 xx 10^(6)` cm, what is radius of the molecules (Given number of molecules per `cm^(3) = 2·69 xx 10^(19)`).

Options

A. `4·362 xx 10^(-8)` cm
B. `2·181 xx 10^(-8)` cm
C. `8.724xx10^(-8)` cm
D. None of these.

Answer

A

Explanation

Mean free path is `lamda=1/(sqrt2pind^(2))`
`therefored^(2)=1/(sqrt2pinlamda)`
`=1/(1·414 xx 3.142 xx 2·69 xx 10^(19) xx 1.1 xx 10^(-6))`
`rArrd=8.724xx10^(-8)` cm
Thus correct choice is (a).