Learning objective
Explain chemical reactions, reproduce the worked example and justify a decision in the case study.
Before you begin
Matter and atoms
Understand
A chemical reaction turns reactants into products by rearranging atoms. A balanced equation conserves the number of each atom type; coefficients indicate proportions.
Worked example
2 H₂ + O₂ → 2 H₂O: each side contains 4 hydrogen atoms and 2 oxygen atoms. This is a symbolic exercise, not a home experiment.
Analysis and common mistakes
Changing H₂O to H₂O₂ to balance an equation changes the substance. Adjust coefficients, not subscripts.
Case study — reasoning
Balance N₂ + H₂ → NH₃: N₂ + 3 H₂ → 2 NH₃. Each side contains two N atoms and six H atoms.
Knowledge check
Summary
A chemical reaction turns reactants into products by rearranging atoms. A balanced equation conserves the number of each atom type; coefficients indicate proportions.
Sources for further study and verification
AI-assisted draft · Educator review not completed · Unofficial supplementary resource