FREE LEARNING SERIES
Chemistry: from particles to reactions
Explain the materials around you, separate mixtures and understand how atoms are conserved in reactions.
4 lessons · Learn at your own pace
Begin the first lesson →
Learn, practise, explain
Try the exercise before reading its explanation. Answer the self-check questions in your own words, then compare your reasoning with the answers. Revisit any difficult section before moving on. No account or payment is needed.
- 01
Matter, particles and changing states
A puddle shrinks, a cold bottle becomes wet, and a balloon keeps its shape. One particle model connects these everyday observations while also explaining what the model cannot show.
Learning outcome: Explain solids, liquids, gases, diffusion and changes of state, then use a mass balance and a temperature record to test a particle explanation.
Open lesson → - 02
Atoms, elements and compounds: reading the chemical alphabet
A formula is a compact statement about composition. Learn to read its symbols before calculating, and distinguish the number of particles from the mass of a substance.
Learning outcome: Classify particle models, interpret subscripts and coefficients, and calculate atom counts and approximate molecular masses with meaningful units.
Open lesson → - 03
Mixtures, solutions and choosing a separation method
Clear water can still contain dissolved substances. Learn to ask what differs between components before deciding whether settling, filtering, crystallising or distilling could separate them.
Learning outcome: Distinguish solutions, suspensions and colloids, calculate mass percentage, and justify a sequence of separation steps without confusing clarity with purity.
Open lesson → - 04
Chemical reactions: new substances, conserved atoms
Rusting and melting both change what we see, but only one forms new substances. Learn to use chemical identity, atom counts and a clear system boundary to explain the difference.
Learning outcome: Interpret reaction evidence, balance simple equations without changing formulas, and explain apparent mass gains or losses by tracing matter across a boundary.
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