The correct balanced chemical equation for the reactions you've mentioned would be:
Zn + O2 → 2ZnO
2B + O2 → 2BaO
BaO + H2O → Ba(OH)2
The correct balanced chemical equation for the reactions you've mentioned would be:
Zn + O2 → 2ZnO
2B + O2 → 2BaO
BaO + H2O → Ba(OH)2