Key Concepts: Balancing Equations

Core Definitions

• Law of Conservation of Mass: Matter cannot be created or destroyed; atoms must balance on both sides.
• Coefficient: A number placed in front of a formula to balance atoms (e.g., 2H₂O).
• Subscript: A number within a formula showing how many atoms of an element are in a molecule; NEVER change subscripts.
• Balancing Steps: 1) Write the unbalanced equation. 2) Count atoms on each side. 3) Add coefficients to balance. 4) Verify.
• Diatomic Elements: Elements that exist as pairs: H₂, N₂, O₂, F₂, Cl₂, Br₂, I₂ (remember HONClBrIF).
• Balanced Equation: An equation with equal numbers of each type of atom on both sides.