8.25e-3 mol * 6.02e23 Al(NO3)3 molecules/mol * 9 O atoms/Al(NO3)3 molecule = 4.47*1022 O atoms Solution 8.25e-3 mol * 6.02e23 Al(NO3)3 molecules/mol * 9 O atoms/Al(NO3)3 molecule = 4.47*1022 O atoms.Read less