M of N in 7.13g of ((NH4)3PO4)?

1g of the molecule has 3 N atoms, 1 atom of N weighs 14 / 6.023 x 10^23 , therefore 1g of ammonium phosphate has 3 x 6.023 x 10^23 / 14 g of nitrogen, ie 7.13 g of ammonium phosphate has 7.13 x 3 x14/ 6.023 x 10^23 g = 49.71 * 10 ^ -23 g( so low)