Equation balancing sprint
Chemical equations must obey the law of conservation of mass: the same number of each atom on both sides. In this game you are the balancer, filling in coefficients against the clock while the atom counter keeps score. Win by thinking like a chemist: count atoms, adjust coefficients, and never touch the subscripts.
Balance: H2 + O2 -> H2O
How to play
An unbalanced equation appears with empty coefficient slots.
Tap the slots to set each coefficient from 1 to 9.
The atom counter shows both sides live as you adjust.
Lock in your answer when both sides match; faster answers earn bonus points.
Stuck? Use a hint to reveal one correct coefficient at a cost.
Scoring
Each balanced equation earns 100 points plus a speed bonus of up to 50 points. Hints cost 25 points each. Three mistakes in a level restart that level.
Levels
Warm-up
Simple synthesis and decomposition with small whole-number coefficients.
Combustion crew
Combustion and single replacement with larger coefficients.
Ion wrangler
Equations with polyatomic ions and trickier atom counts.
Redox master
Redox equations in acidic conditions for experts.
What chemistry did you just use?
Balancing works because atoms are neither created nor destroyed in a chemical reaction. You learned to adjust coefficients, never subscripts, and to save hydrogen and oxygen for last in many equations. A balanced equation is the foundation of every stoichiometry calculation, because the coefficients are the mole ratios the reaction actually follows.
Key concepts
- Conservation of mass in chemical reactions
- Coefficients change amounts; subscripts define the substance
- Counting atoms on each side of an equation
- Polyatomic ions can be balanced as units