Final answer:
The chemical equation H₂(g) + O₂(g) → 2 H₂O(l) is balanced because it conserves mass, with equal numbers of each type of atom on both sides, and the total charge is the same on both sides, which complies with the Law of Conservation of Mass.
Step-by-step explanation:
To answer the student's query, let's consider a fundamental concept of chemistry, which is the balancing of chemical equations. A chemical equation is considered balanced when it conforms to the Law of Conservation of Mass, meaning that there are equal numbers of atoms for each element on both the reactant and product sides of the equation. Additionally, in a balanced equation, the total charge must be the same on both sides if the substances involved are ionic.
Looking at the provided example, H₂(g) + O₂(g) → 2 H₂O(l), we can see that the equation is balanced as there are two hydrogen atoms on the reactant side (one H₂ molecule) and four hydrogen atoms on the product side (two H₂O molecules), which align with the coefficient of 2 in front of the water molecule. Similarly, there are two oxygen atoms in the reactant O₂ molecule, and these are balanced by the two oxygen atoms found within the two H₂O molecules on the product side.
Therefore, as every chemical equation must be balanced to be correct, we can say that the equation above is indeed balanced because it conserves both mass and charge, fulfilling all required conditions. To further prove the conservation of mass, one would show that the mass of the reactants equals the mass of the products.