AQA · GCSE · Chemistry

1 Atoms, elements and compounds: read the chemical symbols 2 Balance equations by conserving each element 3 Higher Tier: conserve charge in ionic and half equations 4 Separate insoluble solids and recover dissolved solutes 5 Choose distillation or chromatography from the mixture 6 Atomic models change when evidence challenges predictions 7 Proton number identifies the element; electrons determine net charge 8 Isotopes, ions and the scale of the nucleus 9 Relative atomic mass: weight each isotope by its abundance 10 Electronic structure of the first twenty elements 11 Periodic positions follow proton number and electron structure 12 Mendeleev: gaps and testable predictions 13 Metals and non-metals: properties, position and ions 14 Group 0: stable shells and boiling-point predictions 15 Group 1: reactions of lithium, sodium and potassium 16 Group 7: molecules, compounds and opposite trends 17 Halogen displacement: predict before observing 18 Chemistry-only: transition metals compared with Group 1 19 Chemistry-only: variable ions, colours and catalysts

1 Particles, bonding and bulk properties 2 Three strong bonds: identify the attracted particles 3 Ionic dot-and-cross diagrams: transferred electrons and charges 4 Giant ionic lattices: formulae and model limits 5 Shared pairs: hydrogen, chlorine, oxygen and nitrogen 6 Water, ammonia, methane and larger covalent structures 7 Metallic bonding: a giant structure with mobile electrons 8 States and changes: energy overcomes particle attractions 9 Higher Tier: what the solid-sphere particle model omits 10 State symbols: aqueous is a solution, not a pure liquid 11 Ionic properties: strong lattices and mobile ions 12 Small molecules: distinguish bonds from intermolecular forces 13 Polymers: long molecules and attractions between chains 14 Giant covalent structures: connections continue through the solid 15 Metals and alloys: distort the layers to resist sliding 16 Metal conduction: electrons transfer charge and thermal energy 17 Diamond: four bonds per carbon in a rigid network 18 Graphite: strong layers, weak interlayer attractions and mobile electrons 19 Graphene: one strong conducting carbon layer 20 Fullerenes and nanotubes: hollow carbon shapes and uses 21 Chemistry-only: nano sizes and surface-area-to-volume ratio 22 Chemistry-only: evaluate a nanoparticle application from evidence

1 Amounts, equations and limiting reagents 2 Conservation of mass: count the complete system 3 Relative formula mass and the mass percentage of an element 4 An open vessel: explain mass entering or escaping as gas 5 Repeated measurements: mean, spread and estimated uncertainty 6 Higher Tier: moles connect mass to stated particles 7 Higher Tier: use the equation ratio between two mole amounts 8 Higher Tier: derive balancing numbers from reacting masses 9 Higher Tier: find which reactant limits the product 10 Solution concentration by mass: convert volume before calculating 11 Higher Tier: explain how mass and volume change concentration 12 Chemistry-only: percentage yield compares recovered and possible product 13 Higher Tier, Chemistry-only: derive the theoretical yield first 14 Chemistry-only: atom economy follows the balanced reaction 15 Higher Tier, Chemistry-only: choose a reaction pathway from several criteria 16 Higher Tier, Chemistry-only: concentration in moles per solution volume 17 Higher Tier, Chemistry-only: titration concentrations follow the equation ratio 18 Higher Tier, Chemistry-only: gas volumes at room temperature and pressure

1 Redox and electrolysis 2 Titration and a defensible concentration 3 Metal oxides: oxidation gains oxygen, reduction loses it 4 The reactivity series: compare reactions at room temperature 5 Displacement evidence: build a consistent metal order 6 Extracting metals: carbon can reduce suitable metal oxides 7 Higher Tier: displacement as electron loss and gain 8 Acids with metals: choose the salt and hydrogen products 9 Higher Tier: hydrogen ions are reduced in acid–metal reactions 10 Neutralisation: select products and balance salt charges 11 Required Practical 1: prepare pure, dry soluble salt crystals 12 The pH scale and hydrogen–hydroxide neutralisation 13 Chemistry-only Required Practical 2: measure reacting volumes 14 Higher Tier, Chemistry-only: determine acid concentration from RP2 data 15 Higher Tier: acid strength differs from acid concentration 16 Electrolysis: mobile ions move to oppositely charged electrodes 17 Molten binary compounds: metal at the cathode, non-metal at the anode 18 Aluminium extraction: a molten mixture and a consumed carbon anode 19 Aqueous electrolysis: water-derived species change the products 20 Required Practical 3: test an electrolysis-product hypothesis 21 Higher Tier: electrode half equations conserve atoms and charge

1 Energy transfers: explain warming and cooling 2 Energy transfers: explain warming and cooling 3 Required practical 4: investigate temperature changes in solutions 4 Reaction profiles: distinguish the barrier from the overall change 5 Higher Tier: count bonds before calculating the energy change 6 Separate Chemistry: cells produce a potential difference 7 Separate Chemistry: choose cells using lifespan and charging evidence 8 Separate Chemistry: evaluate a continuously supplied fuel cell 9 Higher Tier: combine hydrogen fuel-cell half equations

1 Rates, catalysts and reliable endpoints 2 Dynamic equilibrium: equal rates, continuing reactions 3 Mean rates: use the change over the chosen interval 4 Higher Tier: calculate tangent gradients and molar rates 5 Five rate factors: change the conditions, keep comparisons fair 6 Required practical 5: test concentration with gas-volume curves 7 Required practical 5: compare a defined disappearing-cross endpoint 8 Collision theory: concentration and reacting-gas pressure 9 Temperature and solid size: explain two different rate effects 10 Catalysts: a lower barrier, the same overall energy change 11 Reversible reactions: the products can reform the reactants 12 Reverse reactions: energy transfers reverse direction 13 Dynamic equilibrium: equal rates, continuing reactions 14 Higher Tier: predict the response to an equilibrium disturbance 15 Higher Tier: add a reactant or remove a product 16 Higher Tier: warming favours the endothermic direction 17 Higher Tier: count gaseous coefficients before predicting a shift

1 Organic structures and reaction pathways 2 Crude oil: a finite mixture, not one compound 3 Alkanes: connect the formula to the displayed bonds 4 Fractional distillation: separate by evaporation and condensation 5 Hydrocarbon size: boiling point, viscosity and flammability 6 Complete combustion: conserve atoms when hydrocarbons burn 7 Cracking: chemical change makes useful smaller molecules 8 Chemistry-only: recognise the first four alkenes 9 Chemistry-only: hydrogen addition and alkene combustion 10 Chemistry-only: chlorine, bromine and iodine addition 11 Chemistry-only: steam addition forms an alcohol 12 Chemistry-only: alcohol structures, names and uses 13 Chemistry-only: four observations for the first alcohols 14 Chemistry-only: yeast fermentation produces aqueous ethanol 15 Chemistry-only: recognise acids and explain carbonate observations 16 Chemistry-only: an acid and an alcohol form an ester 17 Higher Tier: carboxylic acids are only partially ionised 18 Chemistry-only: an alkene becomes an addition polymer 19 Chemistry-only: keep side groups when drawing a repeating unit 20 Higher Tier: two-ended monomers form a polyester 21 Higher Tier: amino acids join to form polypeptides 22 Chemistry-only: DNA is made from nucleotide monomers 23 Chemistry-only: match natural polymers to their monomers

1 Chemical tests and analytical confidence 2 Chemical purity: use melting and boiling evidence 3 Formulations: each measured component has a purpose 4 Chromatography: phases, spot positions and Rf 5 Required practical 6: separate and identify actual food dyes 6 Gas identification: hydrogen gives a squeaky pop 7 Gas identification: oxygen relights a glowing splint 8 Gas identification: carbon dioxide clouds limewater 9 Gas identification: chlorine bleaches damp litmus 10 Chemistry-only: identify five metal ions by flame colour 11 Required practical 7: identify both ions in an actual unknown salt 12 Chemistry-only: colour and excess alkali identify metal hydroxides 13 Chemistry-only: balance insoluble-hydroxide formation equations 14 Chemistry-only: identify carbonate through its carbon dioxide 15 Chemistry-only: acidified silver nitrate distinguishes three halides 16 Chemistry-only: acidified barium chloride detects sulfate 17 Chemistry-only: accuracy, sensitivity and speed of instruments 18 Chemistry-only: match emission lines and use calibration data

1 Atmosphere, resources and life-cycle decisions

1 Atmosphere, resources and life-cycle decisions