The answer of given question is 0.13 mol
1 mol of chlorine (Cl) contain =[tex]6.022^{23} N_{A} atoms[/tex] atoms (Avogadro Number)
So, we have to determine how many moles of Cl will be contain for [tex]0.79 * 10^{23} N_{A}[/tex]atoms.
As we know unit method
[tex]6.022^{23} N_{A} = 1 mol of chlorine (Cl)[/tex]
[tex]1 N_{A} atom = 1/6.022^{23} N_{A}[/tex]}
[tex]0.79 * 10 ^{23} N_{A} = 1 mol * 0.79^{23} N_{A}/6.022^{23} N_{A}[/tex]
[tex]0.79* 10 ^{23} N_{A} = 0.13 mol[/tex]
So, the answer is 0.13 mol
