mass= density *volume= 2.33*0.1*0.1*0.01 = 2.33*10-4gms atomic mass of Si = 28.1 amu moles of Si =2.33*10-4/28.1 = 8.29*10-6 number of atoms =8.29*10-6*6.023*1023= 5*1018 atoms Solution mass= density *volume= 2.33*0.1*0.1*0.01 = 2.33*10-4gms atomic mass of Si = 28.1 amu moles of Si =2.33*10-4/28.1 = 8.29*10-6 number of atoms =8.29*10-6*6.023*1023= 5*1018 atoms.