Answer:
H2+02--->H20
This equation is not balanced because in the reactant there are two oxygen while in the product oxygen has only one atom. For balancing oxygen we have to put value of 2 in front of water in the product but now hydrogen is imbalance so we have to put 2 in front of hydrogen in the reactant. The balance equation is given below.
2H2 + 02-----------> 2H20
