Calculate the total number of atoms contained in each of the following cases: I'm clueless :(?

ok, what you have to know for this is that 1 mole of any substance represents 6.02 X 10^23 atoms. So, simply with the first one for example, multiply 100X(6.02X10^23) to get 6.02X10^21 atoms. To be honest i'm lost on how to do d and e, but b and c should work just by multiplying the number of moles by 6.02X10^23. Also, of course c needs to be converted to moles first. i'm not quite sure how to convert d or e to moles is the only thing. So, hope this helps.