Chemistry

Solids, liquids and gases in the particle model

Particle arrangement, movement and energy in each state

Melting and freezing explained by particles

Boiling and condensing explained by particles

Sublimation and deposition explained by particles

Changes of state are physical and reversible

Diffusion in gases using the particle model

Diffusion in liquids using the particle model

Explaining gas pressure using particle collisions

Physical changes vs chemical changes (particle-level view)

Why the “hard sphere” particle model has limitations

Particle model limitations: forces, spacing and particle size

Dalton’s atomic model

Thomson’s plum pudding model

Rutherford/Geiger–Marsden alpha scattering experiment

The nuclear model: what it explained and what it didn’t

Bohr’s electron shell model

Why atomic models change over time (evidence and revision)

Nucleus vs electron cloud: where mass and charge are

Orders of magnitude: typical atom size (10⁻¹⁰ m)

Proton, neutron, electron: charges and relative masses

Atomic number and mass number

Isotopes and isotope notation

Calculating protons, neutrons and electrons in atoms

Ions: what changes when ions form

Calculating protons, neutrons and electrons in ions

“Pure” in chemistry vs “pure” in everyday language

Elements, compounds and mixtures: what counts as pure

Using melting point to identify purity

Why impurities change melting point (range + lower mp)

Relative atomic, molecular and formula mass

Calculating relative formula mass from a formula

Using relative masses inside balanced equations

Empirical formula from atom ratios

Empirical formula from models/diagrams

Formulations as useful mixtures

Alloys as formulations (why alloys are useful)

Filtration: separating insoluble solids from liquids

Crystallisation: making a solid from solution

Simple distillation: separating a solvent from a solution

Fractional distillation: separating liquids with different boiling points

Choosing separation methods from substance properties

Paper chromatography: setup and how separation happens

TLC chromatography: setup and spotting

Mobile phase vs stationary phase

Interpreting a chromatogram (spots, components)

Calculating and comparing Rf values

Using chromatography to test purity

Choosing chromatography methods (paper/TLC/gas) for context

Metals vs non-metals: key physical properties

Metals vs non-metals: chemical behaviour (ions/oxides)

Electron shells and the periodic table (group/period meaning)

Atomic number and electron arrangement link

Ionic bonding: electron transfer and ion formation

Ionic lattices: why ionic compounds aren’t “molecules”

Covalent bonding: sharing electrons in molecules

Metallic bonding: positive ions and delocalised electrons

Polymers as giant molecules (repeat units idea)

Giant covalent vs simple molecular substances

Dot-and-cross diagrams for simple covalent molecules

Dot-and-cross diagrams for binary ionic compounds

From ion charges to ionic formulae (criss-cross method)

Comparing bonding/structure types across substances

Representations and models: strengths and limitations

2D vs 3D structures (why shape matters)

Mendeleev’s table: what he got right (patterns)

Modern periodic table: why atomic number matters

Carbon’s four covalent bonds: why it matters

Carbon chains and rings: many organic compounds

Diamond structure and key properties

Graphite structure and key properties

Graphene structure and key properties

Fullerenes structure and key properties

Bond strength vs intermolecular forces (what each controls)

Explaining mp/bp using bonds and intermolecular forces

Using data to predict state at given conditions

Ionic solids: structure and properties (mp, conductivity)

Simple molecular substances: structure and properties

Giant covalent substances: structure and properties

Metals: structure and properties (conductivity, malleability)

Polymers: structure and properties (flexibility, melting range)

Nanoparticles: size and scale (standard form focus)

Surface area to volume ratio at the nanoscale

Uses of nanoparticles (properties-led examples)

Risks/uncertainties of nanoparticles (size changes behaviour)

Using symbols to write formulae for elements

Writing formulae for simple covalent compounds

Writing formulae for ionic compounds (from charges)

Writing balanced symbol equations from word equations

Using conservation of mass to balance equations

State symbols: (s), (l), (g), (aq)

Half equations: what they represent

Writing half equations for simple processes

Common ions: recognising and using ion formulae

Deducing compound formulae from ions in a question

Writing balanced ionic equations (cancel spectator ions)

Avogadro constant: meaning (standard form)

The mole: what it measures

Converting mass to moles (and back)

Conservation of mass in reactions

Explaining mass change in open systems (gas exchange)

Stoichiometry from a balanced equation (mole ratio)

Limiting reactant: identifying what runs out first

Calculating masses from equations

Exothermic reactions: temperature rise of surroundings

Endothermic reactions: temperature fall of surroundings

Energy transfer vs “energy used up” (correct language)

Reaction profiles: exothermic vs endothermic

Activation energy on a reaction profile

Bond breaking needs energy (endothermic step)

Bond making releases energy (exothermic step)

Overall energy change: making minus breaking

Bond energy calculations for reaction energy change (Higher)

Comparing reactions using reaction profiles

Oxidation and reduction in terms of oxygen

Identifying oxidised and reduced species (oxygen definition)

Oxidising agents and reducing agents (oxygen definition)

Oxidation and reduction in terms of electrons

Identifying oxidised and reduced species (electron definition)

Acids in water: hydrogen ions

Alkalis in water: hydroxide ions

Neutralisation: acid + alkali/base → salt + water

Ionic equation for neutralisation: H⁺ + OH⁻ → H₂O

Acids + metals: predicting products and balancing equations

Acids + carbonates: predicting products and balancing equations

Concentrated vs dilute acids (amount per volume)

Strong vs weak acids (degree of ionisation)

pH scale: what it measures

Neutrality, acidity and alkalinity (whole-number pH)

pH and [H⁺]: factor of ten rule

Measuring pH with indicators (universal indicator)

Measuring pH with a pH probe/meter

Electrolytes, ions, and why ionic liquids conduct

Cations and anions: direction of movement

Cathode and anode: identifying each electrode

Products with inert electrodes (metals/H₂ at cathode; non-metals at anode)

Molten binary ionic electrolysis: predicting products

Aqueous electrolysis: competing species idea

Products for aqueous NaCl (brine) electrolysis

Products for aqueous CuSO₄ electrolysis (inert electrodes)

Explaining products using ions present and discharge competition

Writing half equations for electrode reactions

Electrolysis and redox (electron gain/loss at electrodes)

Group 1: key physical and chemical properties

Group 1 trends down the group (reactivity pattern)

Group 7: key physical and chemical properties

Group 7 trends down the group (reactivity pattern)

Group 0: key physical and chemical properties (inert behaviour)

Group 0 trends down the group (bp/density patterns)

Explaining group trends using outer-shell electrons

Transition metals: general properties (density, mp, reactivity)

Transition metal ions: coloured compounds and variable charges

Transition metals as catalysts (why useful)

Predicting reactivity from periodic table position

Metal + water reactions: patterns and predictions

Metal + dilute acid reactions: patterns and predictions

Reactivity series: what it is and how it’s used

Displacement reactions between metals and metal salts

Using experiments to deduce metal reactivity order

Testing oxygen (positive test + why it works)

Testing hydrogen (positive test + why it works)

Testing carbon dioxide (positive test + why it works)

Testing chlorine (positive test + why it works)

Testing carbonate ions (acid test + CO₂ confirmation)

Halide tests with silver nitrate (Cl⁻, Br⁻, I⁻)

Sulfate test with barium ions

NaOH cation tests: calcium

NaOH cation tests: copper

NaOH cation tests: iron(II)

NaOH cation tests: iron(III)

NaOH cation tests: zinc (including solubility points)

Flame tests: method and safety

Flame colours: Li⁺, Na⁺, K⁺, Ca²⁺, Cu²⁺

Identifying unknowns from multiple test results

Instrumental methods: speed, accuracy, sensitivity

Interpreting instrumental results using references

Reading simple mass spectrometry-style charts (pattern matching)

Concentration in mol/dm³: what it means

Calculating mol/dm³ from mass, formula mass, and volume

Converting volume units (cm³ ↔ dm³)

Concentration in g/dm³: meaning and use

Preparing a standard solution (core technique)

Titration apparatus and setup (burette, pipette, indicator)

Identifying the end point (colour change judgement)

Titration calculations using mole ratios

Gas moles and gas volume relationship

Molar gas volume at RTP (24 dm³): correct use

Calculating gas volumes from a balanced equation

Theoretical yield from reactant mass

Actual yield vs theoretical yield

Percentage yield calculations

Atom economy: definition

Atom economy calculations from equations

Choosing pathways using data (yield, atom economy, rate, eqm, by-products)

Rate of reaction: what it measures

Collision theory basics (frequency and energy)

Measuring rate by gas volume collected

Measuring rate by mass loss

Measuring rate by precipitation (visibility)

Measuring rate by colour change/time

Plotting rate graphs correctly (units and axes)

Interpreting rate graphs (steepness and completion)

Mean rate over an interval

Instantaneous rate using tangents/gradients (Higher)

Effect of concentration on rate (collision theory)

Effect of temperature on rate (collision theory)

Effect of surface area on rate (collision theory)

Effect of pressure on gas reactions (collision theory)

Catalysts: what they do and don’t do

Catalysts and activation energy (reaction profile view)

Designing a fair test for rate (controls and repeats)

Reversible reactions: symbol and meaning

Closed systems and why they matter for equilibrium

Dynamic equilibrium: forward rate equals reverse rate

Le Chatelier: changing concentration

Le Chatelier: changing temperature

Le Chatelier: changing pressure (gas equilibria)

Using equilibrium shifts to increase yield

“Best conditions” problems: yield vs rate vs cost trade-offs

Using carbon to extract metals (reduction of oxides)

Extracting iron: principles (carbon in reactivity series)

Extracting non-ferrous metals by reduction (principles + example)

Why some metals must be extracted by electrolysis

Electrolysis extraction: basic industrial principles

Bioleaching: how bacteria help metal extraction

Phytomining: using plants to accumulate metals

Comparing biological and traditional extraction methods

Haber process: reactants and products

Haber process: catalyst and conditions

Haber process: equilibrium (yield vs rate trade-off)

Why the Haber process matters for food production

NPK fertilisers: what N, P and K do for crops

Fertiliser production as integrated industrial processes

Making fertilisers in lab vs industry

Contact process: why we make sulfuric acid

Contact process: steps, catalyst and conditions

Contact process: equilibrium (yield vs rate trade-off)

Graphs of conditions vs rate (industry context)

Choosing industrial conditions using cost, energy, eqm and rate

Life-cycle assessment: included stages

Using LCA data to make a judgement

Recycling for a different use (why viable)

Factors affecting recycling decisions (economic + environmental)

Key alloys: steel, brass, bronze, solder, duralumin

Corrosion: what it is and when it happens

Rusting conditions for iron (water + oxygen)

Preventing corrosion using barriers (paint/oil/plastic)

Preventing corrosion using galvanising/plating

Preventing corrosion using sacrificial protection

Functional groups: spotting in structures

Homologous series: what makes a family

Alkanes: names and displayed structures (first four)

Alkenes: names and displayed structures (first four)

Alcohols: names and displayed structures (first four)

Carboxylic acids: names and displayed structures (first four)

Predicting formulas/structures in a homologous series

Hydrocarbon combustion: products and equations

Bromine test for alkenes (addition across C=C)

Hydrogenation of alkenes (addition across C=C)

Oxidising alcohols to carboxylic acids (KMnO₄ idea)

Addition polymerisation: monomer to polymer (repeat units)

Drawing repeat units with [ ]ₙ notation

Deducing the monomer from an addition polymer

Condensation polymerisation: small molecule loss

Polyesters and polyamides as condensation polymers (block diagrams)

Making condensation polymer in lab (e.g. nylon practical)

DNA: polymer of nucleotides (names of nucleotides)

Natural polymers: sugars and amino acids (examples)

Functional groups: why reactions can be predicted

Fractional distillation of crude oil: how it works

Naming crude oil fractions (core set)

Fraction boiling points: size + intermolecular forces

Crude oil fractions as alkane mixtures (CnH2n+2)

Crude oil as finite petrochemical feedstock

Modern dependence on hydrocarbons (case examples)

Cracking: why we do it (demand vs supply)

Cracking conditions (overview)

Useful cracking products (alkenes and fuels)

Chemical cells: why they produce a potential difference

Hydrogen–oxygen fuel cell chemistry (overall reaction)

Fuel cells: pros and cons for given uses

Evidence for early atmosphere formation

How atmospheric composition changed over time

How an oxygen-rich atmosphere developed

Greenhouse effect: radiation interacting with atmosphere

Evidence for human causes of climate change (correlations)

Uncertainties in climate evidence (meaning of uncertainty)

Effects of increased CO₂ and CH₄ on climate

Mitigating climate change (strategies and trade-offs)

Major CO sources and why CO is harmful

Major SO₂ sources and why SO₂ is harmful

Major NOx sources and why NOx are harmful

Particulates: sources and health/environment effects

Potable water: meaning

Fresh water treatment (filtration/chlorination overview)

Treating wastewater: what needs removing

Desalination: technique and energy/cost trade-offs

Lab safety basics: hazards, risks and control measures

Writing a simple method that controls variables

Variables: independent, dependent, control

Accuracy, precision, repeatability, reproducibility

Recording results in tables with correct units

Choosing equipment to reduce uncertainty

Drawing and interpreting line graphs for chemistry data

Calculating gradients and using them as rates

Significant figures in chemistry calculations

Scientific diagrams: clear apparatus

Planning a metals reactivity investigation

Using observations to rank metals by reactivity

Displacement reactions: comparative evidence

Writing conclusions that match evidence

Setting up an electrolysis circuit safely

Identifying products at electrodes from observations

Using ion ideas to explain products

Setting up paper/TLC chromatography correctly

Using Rf values to compare samples

Using chromatography to assess purity

Filtration and crystallisation in practice

Simple distillation in practice

Choosing a separation route for a mixture

NaOH tests for cations: safe and systematic

AgNO₃ tests for halides: safe and systematic

Ba²⁺ tests for sulfate: safe and systematic

Using results to identify an unknown sample

Carrying out a titration with consistent technique

Getting concordant results and justifying reliability

Using titration results for calculations

Making a soluble salt by neutralisation and crystallisation

Making an insoluble salt by precipitation and filtration

Drying and obtaining a pure, dry sample

Measuring rate by gas collection or mass loss

Designing a rates investigation (one factor at a time)

Presenting and analysing rates data (graphs and gradients)