Assuming that the reactants are:
(NH4)2SO4 (aq) + Ba(NO3)2 (aq)
and the products are:
BaSO4 (s) + 2NH4NO3 (aq),
then you will have to determine which product is insoluble. You should have access to solubility rules to help you determine this.
According to the solubility rules, the following elements are considered insoluble when paired with SO4:
Sr^2+, Ba^2+, Pb^2+, Ag^2+, and Ca^2+
Therefore, the precipitate will be BaSO4 (s).
Your protons are correct but it’s 28 neutrons not 27!
I think this is what u need.
1.<span>Cd(NO3)2 + 2NH4Cl -> CdCl2 + 2NO3NH4
2.</span>H3PO4(aq) + 3Ca(OH)2(aq) -> Ca3(PO4)2(aq) + 6H2O