Answer :
Each mole has [tex]6.022 *10^{23} [/tex] atoms.
[tex] \frac{1}{8}* 10^{-2}*6.022* 10^{23} = 7.5* 10^{20} [/tex] atoms
[tex] \frac{1}{8}* 10^{-2}*6.022* 10^{23} = 7.5* 10^{20} [/tex] atoms
One mole of anything is 6.022*10^23 of that thing. so just multiply 6.022*10^23 by 0.00125 to find your answer.