The decomposition of water into hydrogen gas h2 and oxygen gas o2 can be modeled by the balanced chemical equation
a) h2 + o2 → h2o
b) h2o → h2 + o2
c) 2h2 + o2 → 2h2o
d) 2h2o → 2h2 + o2

Explanation:

Decomposition is reaction where a single reactant produces two or more than two products.

According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.

The balanced chemical equation for the decomposition of water is :

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.