* Changing subscripts changes the chemical formula of the compound. This means you are no longer representing the same substance. For example, changing H₂O to H₂O₂ changes water into hydrogen peroxide, a completely different compound with different properties.
* Subscripts indicate the number of atoms of each element in a molecule. Changing them alters the composition of the molecule, not just the number of molecules.
* Balancing equations is about conserving mass and atoms. You need to ensure that the same number of atoms of each element appears on both sides of the equation, but without altering the identity of the reactants and products.
Instead of changing subscripts, we use coefficients. These numbers are placed in front of the chemical formulas and indicate the number of molecules or formula units involved in the reaction. By adjusting coefficients, we can ensure the same number of atoms of each element on both sides of the equation without changing the chemical formulas.
Example:
Unbalanced Equation: H₂ + O₂ → H₂O
Balanced Equation: 2H₂ + O₂ → 2H₂O
Here, we used the coefficients '2' in front of H₂ and H₂O to balance the equation. We now have 4 hydrogen atoms and 2 oxygen atoms on both sides of the equation, maintaining the chemical formulas of hydrogen, oxygen, and water.
