Naturally occuring flourine is entirely 19 F but suppose that it were 50% of 19 F and 50 of 20 F. Whether gaseous diffusion of UF6 would then work to separate U235 from U 238.

Hi Vishrant,

if it is entirely 19F then we can seperate U235 and U238 because the molecular weights of UF6 will be 349 and 352 respectively.

But when 50% 19 F and 50% 20F are there then the Fs in UF6 may be in any proposition.

example:

U-235 and 6 20Fs   & U-238 and 3 20Fs + 3 19Fs will have same molecular weights.

similarly we can get the many proportions with U235 and U238 having same molecular weights.... so it is difficult to seperate.