Question

Ca+H2—
Na+O2—
MgO+H2O—
Ba(OH) —?+?
HCe+. Fe —?+?
PBo+Ae—?+?

Answer 1

Ca + H2 -> CaH2
4Na + O2 -> 2Na2O
MgO + H2O -> Mg(OH)2
 Ba(OH)2 -> BaO + H2O
 2HCl + Fe -> FeCl2 + H2
 3PbO + 2Al -> Al2O3 + 3Pb