No of atoms=No of moles ×Avagadro no
[tex]\\ \tt\longmapsto 4\times 6.023\times 10^{23}[/tex]
[tex]\\ \tt\longmapsto 24.092\times 10^{23}[/tex]
[tex]\\ \tt\longmapsto 2.4\times 10^{24}atoms[/tex]