Answer:
Balancing of equation involves making sure the number of atoms of an element on the left hand side(reactant) is equal to the number of atoms of an element on the right hand side(product)
4NH3 + 14O2 → 4NO2 + 6H2O
In the equation above,the number of Oxygen on the left is (14*2)=28 while the number of oxygen on the right is (4*2+6)=14. This makes it an unbalanced equation.