The number of formula units of NaCl are 7. In 1 mole of NaCl there are [tex]6.023\times 10^{23}[/tex] formula unit are present.
Thus, 1 formula unit will be there in [tex]\frac{1}{6.023\times 10^{23}}=1.66\times 10^{-24}[/tex] moles.
and, 7 formula unit will be there in [tex]1.16\times 10^{-23}[/tex] moles.
There is 1 mol of Cl present in 1 mol of NaCl. thus, [tex]1.16\times 10^{-23}[/tex] of Cl will be there in [tex]1.16\times 10^{-23}[/tex] mol of NaCl.
Converting number of moles into number of atoms as follows:
In 1 mole of a substance there are [tex]6.023\times 10^{23}[/tex] atoms of chlorine thus, in [tex]1.16\times 10^{-23}[/tex] mol there will be 7 atoms of chlorine.
Therefore, number of atoms of chlorine will be 7.
