Question

Calculate the no.of moles
(a)3.011 X 10power 23 atoms of He
(b)1.505 X 10power23 of Co2
(c)6.022 X 10power23 atoms of Na (hint :nis equal to N/No)

Answer 1

There are 6.022E23 atoms in a mole of atoms and 6.022E23 molecules in a mole of molecules.
So 3.011E23 atoms x (1 mol/6.022 atoms) = mols He.

b. I don't know. I suspect you made a typo and this is meant to be CO2.

c. This is done the same way as part a. I don't get the hint since you didn't define N/No.