Chemistry · Grades 7–10
Balance equations without changing formulas · Revision sheet
Use coefficients to conserve atom counts.
Learn the idea
Conservation
A chemical equation must preserve each element and net charge.
Coefficients
A coefficient multiplies the whole formula that follows it.
Subscripts
Changing a subscript changes a chemical formula rather than balancing it.
Check
Count every element separately on each side; use the smallest whole-number coefficients when requested.
Explain without looking
- For 2Mg + O₂ → 2MgO, how many moles of MgO correspond to 3 mol Mg consumed?
- Why should an ionic equation also conserve charge?
Further reading and review references
These are reference links, not copied exercises, institutional endorsement or proof of independent review.
Independent educational review required. Grade bands are approximate; these are not officially aligned curricula.