Final answer:
The given equation represents a chemical reaction where water breaks down into hydrogen gas and oxygen gas. To balance the equation, 2 H2O reacts to form 2 H2 and O2.
Step-by-step explanation:
The given equation, H2O → H2 + O2, represents a chemical reaction involving water (H2O) breaking down into hydrogen gas (H2) and oxygen gas (O2) in an unbalanced form. To balance the equation, we need to ensure that the number of atoms of each element is the same on both sides. In this case, the balanced equation would be 2 H2O → 2 H2 + O2.