Atomic structure & the periodic table
The atom – basic structure
Key discoveries which led to the development of the modern model of atomic structure; typical size (order of magnitude) of molecules, atoms & sub-atomic particles; relative mass & charge of sub-atomic particles.
The atom – electronic structure
Energy levels (shells) of electrons, and the unique, discrete (quantised) differences in these energy levels in atoms of different elements, causing unique absorption/emission spectra; occupancy of outer shell & stability.
Definition of and distinction between the terms matter, (pure) substance, element, compound, mixture (in terms of chemical formulae, atoms & molecules & bonding); purity of substances and experimental determination.
Nomenclature of compounds of the first 20 elements from given formulae & calculation of relative formula masses; definition of relative atomic mass, relative molecular mass & relative formula mass; empirical formulae.
Processes and techniques for separation of mixtures; filtration, crystallisation, simple distillation, fractional distillation, paper & thin layer chromatography, including Rf values & interpretation of chromatograms.
The periodic table
Overview of work of Newlands & Mendeleev in the development of the modern periodic table; arrangements of elements into groups & periods in relation to atomic number, electron configuration, and chemical properties.
The alkali metals
The chemical properties of Group I metals, including the chemical reactions of Group I metals with oxygen, chlorine and water, and trends in their reactivities in terms of the electron configurations of their atoms.
Chemical properties of Group VII elements, including their reactions with metals & displacement reactions; trends in reactivity in terms of electron configuration; trends in physical properties (intermolecular bonding).
The transition metals
Properties of transition metals compared with alkali metals, including melting points, densities, strength, hardness & reactivity with oxygen, water & halogens; formation of ions with different charges & coloured compounds.
The noble gases
Low chemical reactivity of Group 0 elements in terms of stable electron configuration; trend in boiling points of noble gases due to differences in electron density of atoms and physical bonding in these monatomic gases.
Structure, bonding & properties
Chemical bonding – covalent
The concept of a bond as a force of electrostatic attraction between particles (atoms, molecules or ions); distinction between chemical & physical bonds; formation of covalent bonds in terms of outer shell electrons.
Chemical bonding – ionic
Formation of ionic bonds by the transfer of electrons between atoms to produce cations and anions; use of the suffixes –ide and –ate in the names of compounds; formulae of ionic compounds; structure of ionic compounds.
Structure & properties – simple covalent molecules
Properties due to shapes/sizes of molecules & physical bond strength; strength of physical vs. chemical bonds; distinction between chemical & physical properties.
Structure & properties – covalent macromolecules
Properties of giant covalent substances (including allotropes of carbon and nanostructures) in terms of arrangements of atoms and covalent vs. intermolecular bonding.
Structure & properties – ionic structures
Physical properties of ionic compounds in terms of strength of ionic bonds (dependent upon relative charge densities of ions) and arrangements of ions in crystal lattice geometry (representation in 2D and 3D diagrams).
Metals – structure, properties & uses
Properties of metals in terms of metallic structure and bonding (electrostatic attractions between cations and delocalised electrons); factors determining strength of metallic bonding; alloys and their properties.
The kinetic theory
Overview of kinetic theory and its use in explaining physical properties of matter in terms of arrangements, motion and physical bonding between particles; changes of state; limitations of the particle model.
Structure & properties – nanoscience
Surface area to volume relationship for different-sized particles and how this affects properties; uses of nano-scale particles related to their structure and properties; possible risks with the use of nanoparticles.
Measuring in Chemistry
Selection & use of appropriate measuring apparatus for chemical measurement at GCSE (including thermometers, measuring cylinders, burettes, etc.); calibration; accuracy, sensitivity & precision; units & conversions.
Rationale for balancing chemical equations in terms of the law of conservation of mass (atoms); use of state symbols; write balanced chemical equations (including use of correct formulae of reactants & products).
Definitions of relative atomic mass, relative formula mass, molecular formula, empirical formula; determination of empirical & molecular formulae from appropriate data (e.g. amounts of reactants, % composition, etc.)
Mass & the mole
Definition of a mole of a substance; Avogadro’s number and its significance; calculation of number of moles of a substance from mass and relative mass data; calculation of percentage of an element in a compound by mass.
Reacting masses, gas volumes and solutions
Deduction of stoichiometry of a reaction from masses, concentrations, volumes pressures, formulae and relative masses of reactants and products; application of law of conservation of mass to reactions in real contexts.
Atom economy and percentage yield
More detail on percentage yield and atom economy; relevance of percentage yield & atom economy in selection of reaction pathways for industrial chemical production; determination of atom economy from chemical equations.
Oxygen & Oxides
Laboratory preparation of oxygen and carbon dioxide; describe the properties of the oxides of carbon, sulphur, group I and group II metals (also hydroxides); describe the chemical properties of metal carbonates.
The reactivity series
Deduction of reactivity series through comparing reactions of metals with water, dilute/concentrated acids, or through displacement reactions; explanation of relative reactivity of metals in terms cation formation.
Metals – extraction
Extraction of metals from compounds in ores in relation to reactivity series; extraction process, illustrated by heating with carbon (including iron) & electrolysis (including aluminium); biological extraction & recycling.
Reduction & oxidation in terms of gain/loss of electrons (including the terms oxidising agent & reducing agent); displacement reactions as redox reactions, in terms of gain or loss of electrons; examples of redox reactions.
Acids & bases
Definition of acids & bases in terms of production of hydrogen and hydroxide ions respectively in aqueous solution; neutralisation reactions between acids, and metals, metal oxides/hydroxides/carbonates; the pH scale.
Formation of salts from neutralisation reactions between acids and metal compounds (oxides, hydroxides or carbonates); practical implications of solubility of reactants or products of such reactions; nomenclature of salts.
Electrolysis as a process in which electrical energy, from a direct current supply, decomposes electrolytes; explanation in terms of reduction & oxidation at anode & cathode (including half equations) with examples.
Chemical Energetics, Kinetics & Equilibria
Energy from reactions (energetics)
Exothermic vs. endothermic reactions in terms of net energy change involved (breaking bonds in reactants and formation of new bonds in products); calculation of overall enthalpy changes; activation energy & reaction profiles.
Chemical Cells & Fuel Cells
Description and explanation of operation of electrical cells (including voltage) in terms of relative reactivities of metals used for electrodes, electrolyte, etc.; rechargeable cells; the hydrogen-oxygen fuel cell.
Rates of reaction
Practical methods for determination of the rate of a reaction and its calculation from appropriate data; drawing/interpreting graphs of reaction rate data; factors affecting reaction rate in terms of collision theory.
Definition of the term “catalyst” in chemistry, and explanation of their action in chemical reactions in terms of changes in activation energy (provision of alternate reaction pathway energetics) and collision theory.
Concept of reversible reactions and dynamic equilibrium; energetics of reversible reactions; effect of changes in temperature, pressure & concentration on position of equilibrium (Le Chatelier’s principle); Haber process.
Crude oil – origin & separation
Formation of crude oil & separation by fractional distillation; names & uses of major fractions; explaining fractional distillation in terms of differences molecular sizes & physical bonding strength in fractions.
Crude oil – hydrocarbon structure
Features of a homologous series, exemplified by alkanes (including nomenclature); molecular, empirical, structural, displayed & skeletal formulae; trends in physical properties in terms of structure & physical bonding.
Complete & incomplete combustion of hydrocarbons and conditions required for either, represented by balanced symbol equations; human & environmental impact of the products of complete & incomplete combustion.
Crude oil – obtaining useful substances
Use of cracking to obtain more useful saturated & unsaturated hydrocarbon products; conditions required for cracking; structure, formulae, nomenclature & reactions of alkenes (halogenation, hydrogenation & polymerisation).
Alcohols, Carboxylic Acids & Esters
Concept of functional group & chemical properties of homologous series; structure, nomenclature, formulae of alcohols, carboxylic acids & esters; chemical properties (e.g. oxidation/reduction of alcohols, esterification).
Synthetic & biological polymers
Addition & condensation polymerisation, including representation of these reactions in chemical equations using standard notation; properties of synthetic & biological polymers in relation to their structure & bonding.
Analysing substances – titrations
Practical aspects of titrations, including selection & use of appropriate indicators; calculation of concentrations of solutions from appropriate titration data; conversion of units for concentration and volume.
Analysing substances – chromatography & spectrometry
More detail on thin layer & paper chromatography; overview & evaluation of instrumental analysis methods (including atomic absorption/emission spectrometry).
Analysing substances – ions & flame tests
Chemical tests for aqueous cations and anions (calcium, copper, iron (II), iron (III), & zinc using NaOH; carbonate & sulphate using barium chloride & HCl; halides using silver nitrate test); flame tests for metal ions.
Resources – reducing use & recycling
Overview of the basic principles of carrying out life-cycle assessments of materials & products, including interpretation of data from such assessments; process and evaluation of viability of recycling of materials.
Principal methods for increasing availability of potable water in terms of the separation techniques used (including ease of treatment of waste, ground & salt water); differences in treatment of ground water & salty water.
Explanation of the process of corrosion with examples, and the conditions which lead to corrosion, and relevance of oxidation; mitigation of corrosion by use of physical barriers, electroplating & sacrificial protection.
Metals – alloys
Definition of alloys as mixtures of metals (and some non-metals) in specific proportions; Physical properties of alloys explained in terms of structure & bonding; uses of metals and alloys related to their properties.
Ceramics, polymers & composites
Comparative properties and uses of composites, glass & clay ceramics and polymers (thermostetting & thermosoftening plastics, HD & LD polyethene, etc.) with examples, in relation to their structures & bonding.
Ammonia – production, uses & fertilisers
More detail about the Haber process and the typical conditions chosen for maximum yield of ammonia at equilibrium in industrial production; importance & industrial production of potassium, phosphate & nitrate fertilisers.
Atmosphere – origin & composition
Processes involved in the gradual change from the early atmosphere of the Earth to its modern composition (including formation of the oceans), including the interpretation of evidence & data relating to these processes.
Atmosphere – human impact
Mechanism for the greenhouse effect and evidence for anthropogenic impact and uncertainties in this evidence base (correlation between change in atmospheric carbon dioxide concentration and fossil fuel consumption).