Build your understanding one small reading at a time. Each available step uses selected sections of an existing lesson, with a reading target of about 4–7 minutes.
No account or completion requirement. Skip ahead to any available reading, or leave for Units whenever you like.
Stage 1 of 9
Start with what chemistry studies and how quantities are measured.
Stage 2 of 9
Connect element symbols with the particles that make up atoms.
Stage 3 of 9
Read particle counts and charges before working with compounds.
Stage 4 of 9
Use the table as a map of the elements.
Foundation reading · ~4 min
Locate the main element categories without learning orbital notation.
Read: Find metals, nonmetals and metalloidsReview if useful. These suggestions never lock a step.
Stage 5 of 9
Begin with outer electrons and simple bonding patterns.
Foundation reading · ~6 min
Use main-group numbers to count valence electrons and read Lewis symbols.
Read: Count outer electronsReview if useful. These suggestions never lock a step.
Foundation reading · ~5 min
Recognize the duet and octet guidelines and common neutral-atom bond counts.
Read: Recognize simple bonding patternsReview if useful. These suggestions never lock a step.
Stage 6 of 9
Connect tiny particles with measurable masses.
Foundation reading · ~6 min
Explain a mole as a fixed particle count and name the particles being counted.
Read: Count particles in molesReview if useful. These suggestions never lock a step.
Foundation reading · ~7 min
Find molar mass from atomic masses and formula subscripts.
Read: Find the mass of one moleReview if useful. These suggestions never lock a step.
Foundation reading · ~7 min
Follow unit cancellation through mass, amount and particle-count conversions.
Read: Connect grams, moles and particlesReview if useful. These suggestions never lock a step.
Foundation reading · ~4 min
Check whether a calculated amount and its reported precision make sense.
Read: Check units, size and roundingReview if useful. These suggestions never lock a step.
Stage 7 of 9
Conserve atoms by changing coefficients, while keeping formulas intact.
Foundation reading · ~7 min
Count each type of atom and change coefficients without changing a substance.
Read: Balance atoms with coefficientsReview if useful. These suggestions never lock a step.
Foundation reading · ~5 min
Clear fractional coefficients and reduce the complete balanced equation.
Read: Finish with whole-number coefficientsReview if useful. These suggestions never lock a step.
Foundation reading · ~4 min
Recognize solid, liquid, gas and aqueous labels in a reaction.
Read: Read physical-state symbolsReview if useful. These suggestions never lock a step.
Stage 8 of 9
Use a balanced equation to relate amounts of different substances.
Foundation reading · ~6 min
Use coefficients as mole ratios and orient a conversion so units cancel.
Read: Read a reaction's mole ratioReview if useful. These suggestions never lock a step.
Foundation reading · ~7 min
Follow mass → moles → mole ratio → mass and round only at the end.
Read: Connect reactant mass to product massReview if useful. These suggestions never lock a step.
Stage 9 of 9
Describe concentration, dissolved ions and simple proton transfer.
Foundation reading · ~7 min
Relate moles of solute to the final solution volume in litres.
Read: Describe solution concentrationReview if useful. These suggestions never lock a step.
Foundation reading · ~5 min
Explain why dilution changes concentration while preserving solute amount.
Read: Dilute a solutionReview if useful. These suggestions never lock a step.
Foundation reading · ~4 min
Interpret an aqueous ionic compound as separated, hydrated ions.
Read: Picture dissolved ionsReview if useful. These suggestions never lock a step.
Foundation reading · ~6 min
Identify the proton donor, proton acceptor and corresponding conjugate pairs.
Read: Recognize acids and basesReview if useful. These suggestions never lock a step.
Foundation reading · ~4 min
Connect a simple acid–hydroxide reaction with salt and water products.
Read: Recognize neutralization productsReview if useful. These suggestions never lock a step.
Orbital filling, resonance, hybridization, multi-step reaction sequences, equilibrium calculations, buffers and AP-style problems are outside this pathway. They remain available in the full lessons and AP study hub when you are ready.