To balance a chemical equation, one must adjust the coefficients to ensure the same number of each element's atoms on both sides, obeying the Law of Conservation of Matter. Subscripts in formulas should never be altered, only coefficients.
To balance a chemical equation, start by identifying the most complex substance. Then, balance elements that appear in only one reactant and one product, adjusting the coefficients to achieve the same number of atoms of this element on both sides. Polyatomic ions that remain unchanged on both sides of the equation can be balanced as a unit. The remaining atoms are balanced last, often ending with the least complex substance. If fractional coefficients are used, multiply through to achieve whole numbers. Throughout this process, it's vital to ensure that you only alter coefficients, not the subscripts in chemical formulas, and to verify that each element has an equal number of atoms on both sides of the equation.
Coefficients are the large numbers placed in front of formulas to balance equations, reflecting the Law of Conservation of Matter. When balancing equations, matter cannot be created or destroyed, which requires an equal number of atoms of each element on both sides. Only the coefficients can be changed, while subscripts must remain unchanged.