🧪 Chemical Reactions

Balance the equation! Use the ▲▼ buttons so both sides have the same number of every atom.

Combination
A + B → AB (2H₂ + O₂ → 2H₂O)

Decomposition
AB → A + B (splits apart, often by heat)

Displacement
A + BC → AC + B (a more reactive metal kicks one out)

Double Displacement
AB + CD → AD + CB (partners swap)

Also: oxidation (gain oxygen) & reduction (loss of oxygen) · rusting = corrosion · food going stale = rancidity

🧠 The Big Idea

Law of conservation of mass: atoms are never created or destroyed — so a balanced equation must have the same count of each atom on both sides.
You balance by changing coefficients (the big numbers in front), never the small subscripts.