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The tables below contain a brief description of all the A-level chemistry pages and content in this site. My aim is to cover all the content in most A-level specifications, so please check back soon as I will be updating this site regularly.

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Atomic structure and chemical formula recap from GCSE.

Atomic structure Recap on the internal structure of atoms from gcse chemistry. Brief discussion on how to calculate the numbers of protons, neutrons, and electrons in atoms and ions.
Recap on the Plum pudding model to Rutherford's nuclear atom Recap on the work of Thomson, Rutherford and Bohr and how they developed a model of the internal structure of the atom.
Isotopes Recap from gcse chemistry on isotopes, their structure and properties. Explanation on how to calculate relative atomic mass.
Finding the formula Recap from gcse chemistry on how to work out the formula for covalent compounds, acids and alkalis.

The mass spectrometer.

Time of flight mass spectrometer (TOF) Overview of the main stages in the operation of a time of flight mass spectrometer - AQA exam board only.
The mass spectrometer Overview of the workings of a single beam mass spectrometer is discussed, along with an explanation of the four key stages in its operation.
Mass spectra Detailed examples of how to analyse the mass spectrum of a compound and common fragmentation patterns for a variety of molecules are discussed. Examples on how to calculate the relative atomic masses of an element are shown.

Electron arrangements in atoms, ionisation energies and trends in atomic radii of atoms.

From the Plum pudding model of the atom to quantum theory Discussion on how emission spectra helped scientists work out the internal structure of atoms. This page discusses the hydrogen emission spectrum and how Bohr used his "new" ideas to explain the emission spectrum for hydrogen.
Electron shells, sub-shells and orbitals An introduction to sub-shells and energy levels within atoms
The shapes of s, p and d-orbitals A discussion on the shapes of the s,p and d-orbitals and also on the reasons why the energy levels for single and multi-electron atoms differ.
The aufbau principle A brief explanation with examples on how to work out the electronic configuration for atoms including transition metals.
Ion formation Explanation with examples on the electron configuration of ions.
Trends in atomic radii A brief visit to help explain and identify the trends in the size of atoms across a period and down a group in the periodic table.
Trends in the ionisation energy for period 3 elements Examples with detailed explanations to discuss the patterns and trends in the ionisation energies for the period 3 elements.
Trends in the ionisation energy for group 2 elements Examples to show the trends in the ionisation energies for the group 2 elements. Also covered is the use of ionisation energies as evidence for the existence of shells and sub-shells with atoms.

The gas laws

The gas laws Overview of Boyle's Law, Charles Law, Avogadro's Law and an explanation of how to use these 3 laws to derive the ideal gas equation.
The ideal gas equation Introduction to the properties of an ideal gas and also how to use the ideal gas equation to calculate the Mr of a substance.


Introduction to ionic bonding Basic introduction to ionic bonding and recap of ion formation and how to draw dot and cross diagrams from gcse chemistry.
The structure and formula of ionic compounds. Overview of the structure of ionic compounds with examples of the different types of ionic lattices. Explanation with examples on how to work out the formula of simple ionic compounds and also ionic compounds containing group ions.
The properties of ionic compounds Recap and overview of the typical properties of ionic substances including: solubility, electrical conductivity and melting points. Short discussion on ion migration.
Covalent bonding overview Recap and overview of covalent bonding from gcse chemistry with examples of dot and cross diagrams for simple molecules.
Explanation with examples on how dative or co-ordinate bonds are formed. Explanation of how dative covalent bonds are formed in a range of different compounds.
Exceptions to the octet rule Examples with explanations as to why some molecules do not follow the Octet rule.
Metallic bonding Discussion on the nature of metallic bonding and the common properties of metals that results from this type of bonding
Electronegativity Introduction to electronegativity and the factors which affects its value.
Polar covalent bonds and electronegativity Discussion on the nature of polar covalent bonding and polar molecules. Bond dipoles and dipole moments are mentioned.
Electronegativity and bond character Explanation of how to use electronegativity values to determine the character of a bond.
Polarisation of ionic bonds Discussion of how large non-metals anions can become polarised and distorted by small metal cations. Introduces idea of ionic bonds with covalent character.
Calculating dipole moments. Explanation of dipole moments in molecules and how to calculate the size of them in simple molecules.

Intermolecular bonding

Types of intermolecular bonding. Explanation of the difference between intramolecular and intermolecular bonding and a brief outline of the three different types of intermolecular forces or bonds.
Van der Waals bonding/dispersion forces Explanation with examples on how Van der Waals forces (London dispersion forces) originate and their effects on the physical properties of substances.
Dipole-dipole interactions Introduction to intermolecular bonding and dipole-dipole interactions.
Hydrogen bonding Explanation of hydrogen bonding with examples of molecules which contain H-bonds. Discussion on the affects of hydrogen bonding on the physical properties of molecules.
Intermolecular bonding and physical properties This page explains and gives examples of how the types of intermolecular bonding present between molecules can affect physical properties such as melting/boiling points, solubility, viscosity and surface tension in liquids..

Crystals, bonding and physical properties

Giant covalent macromolecular structures Diamond and graphite structures are discussed along with differences in the properties of these two allotropes of carbon. Fullerenes and buckyballs are briefly covered.
Molecular crystals Discussion with examples of the properties of covalent substances, including solid molecular crystals. Discussion on how intermolecular bonding may affects the melting and boiling points of covalent molecules as well as their solubility in various types of solvents.

Shapes of molecules

Introduction to shapes of molecules Introduction to the 5 basic shapes found in simple covalent molecules. Discussion of shape and bond angles present in molecules a well as equatorial and axial position in trigonal bipyramidal molecules.
Using VSEPR to find the shapes of molecules Explanation on how to use VSEPR rules to find the shapes of simple molecules without lone pairs or charges.
The affect of lone pairs on the shape of a molecule Discussion on the affects that lone pairs of electrons have only the bond angles and shapes of molecules.
Trigonal bipyramidal molecules and lone pairs This page gives examples on the shapes of trigonal bipyramidal molecules with multiple lone pairs. It discusses axial and equatorial positions in trigonal bipyramidal molecules.
Octahedral molecules and lone pairs Discussion on the affects that lone pairs of electrons have on the shapes of octahedral molecules. Brief discussion on how the presence of multiple bonds in a molecule will affect their shape.
Working out the shape of ions Using VSEPR rules to work out the shape of ions.


Enthalpy changes Discussion with examples on the differences between open and closed systems. The meaning of the term enthalpy is explained with some worked examples. Recap on endothermic and exothermic reactions.
Enthalpies of combustion, formation and standard states Discussion with examples on enthalpies of combustion and formation. Introduction to the idea of standard enthalpy changes and standard states.
Hess's Law Explanation with examples on how to carry out Hess's law types questions using enthalpies of formation and combustion.
Enthalpy changes using mean bond enthalpies Discussion with examples on how to use mean bond enthalpies to calculate enthalpy changes for reactions.
Calorimetry Explanation and worked examples on how to calculate enthalpy changes using asimple calorimeter.
Enthalpy changes in solution Details on how to calculate enthalpy changes for reactions taking place in solution e.g. neutralisation and displacement reactions.

Redox reactions

Oxidation, reduction and redox equations Examples on how to write half-equations for redox reactions. Re-cap from gcse on the meaning of the terms oxidation, reduction, reducing agent and oxidising agent.
Examples of simple redox equations and introduction to oxidising agents Examples on how to write simple half-equations to show oxidation and reduction in chemical reactions. Examples include metal acid reactions and combustion reactions. Examples on oxidation/reduction/redox and introduction to common oxidising agents.
Oxidation numbers Introduction to oxidation numbers with examples on how to work them out for a range of compounds. Discussion of the variety of oxidation numbers for transition metals, including vanadium and chromium.
Redox equations and oxidising agents Examples with half-equations to show the use of potassium dichromate and potassium permanganate as oxidising agents in redox reactions. Help given on how to deal with complex redox equations with example problems and answers provided.

Reversible reactions and equilibrium

Reversible reactions and equilibrium Introduction to open and closed systems, reversible reactions and dynamic equilibrium
Le Chatelier's Principle Explanation with examples of Le Chatelier's principle. Discussion on how temperature, concentration and pressure changes can alter the position of equilibrium.
Equilibrium constants Explanation of what equilibrium constants are and how to write expressions to show them. Also covers how to work out the units of the equilibrium constant Kc.
Calculations based on equilibrium constants How to calculate the equilibrium constant Kc.

The halogens

Halogens- general properties Overview of the basic properties and reactions of the halogens, including: trends in reactivity, solubility, electronegativity and reactions with metals and non-metals.
Halogens- oxidising ability The trends in the oxidising ability of the halogens is discussed along with examples of halogens acting as oxidising agents in displacement reactions.
Halide ions as reducing agents Description of the trends in the reducing abilities of the halide ions with examples and explanations.
Testing for halide ions Details of the silver nitrate test and discussion on the solubilities of halide ions in ammonia solutions.
Disproportionation reactions Examples of disproportionation reactions using the reactions of chlorine with water and sodium hydroxide as examples.

Organic Chemistry

Naming alkanes and branched alkanes. Explanation with examples on how to name straight chain alkane molecules and branched alkanes. This page covers structural isomers-chain isomerism.
Position and functional group isomers. Explanation with examples of the difference between functional group isomers and position isomers.
Nomenclature and functional groups. Diagrams and examples of the main types of functional groups you are likely to meet in A-level chemistry along with advice on how to name molecules.
Fractional distillation of crude oil Explanation of how crude oil is refined into different fractions.
Homolytic and heterolytic bond cleavage Explanation with examples of the difference between homolytic and heterolytic bond fission.
Free radical substitution reactions Explanation with equation to show how free radical substitution reactions happen. Explanation of how different products are obtained using the example of the chlorination of methane.

Organic Chemistry - The alkenes

Sigma and pi bonds Explanation of the difference between sigma and pi bonds, with examples given to show how each type of bond is formed.
Stereoisomers Description of geometric isomers and the cis/trans, E-Z naming systems with a few examples of each.
Cahn-Ingold-prelog rules for naming alkenes A brief outline is given of how the Cahn-Ingold-Prelog rules are used to name substituted alkene molecules. The limitations of the cis/trans naming system for disubstituted alkene molecules is also discussed.
Alkenes and addition reactions Discussion of the mechanism of electrophilic addition reactions to alkenes using bromine and bromine water as examples.
Further Addition reactions Discussion on how alkenes can be used to produce halogenalkanes by reaction with hydrogen halides and also how alcohols can be produced by direct hydration and by the reaction of an alkene with concentrated sulfuric acid. Brief discussion on how alkenes can be oxidised to form diols using potassium permanganate as an oxidising agent.
Predicting products of addition reactions to unsymmetrical alkenes Discussion with examples on how to predict the major and minor products of addition reactions to unsymmetrical alkenes. Examples using Markovnikov's rule.
Hydrogenation of unsaturated molecules A discussion of the mechanism and uses of hydrogenation of carbon carbon double bonds (C=C) in fats and oils.

Organic Chemistry - Halogenalkanes

Introduction to the structure and reaction of halogenalkanes. Introduction to nucleophilic substitution reaction, primary, secondary and tertiary halogenalkanes and an explanation of SN1 and SN2 reaction mechanisms.
Introduction to nucleophilic substitution reaction using halogenalkanes. Introduction to nucleophilic substitution reaction using the hydrolysis of halogenalkanes by water as an example is included here. Details of the practical set-up and results are discussed briefly.
Nucleophilic substitution examples Examples of nucleophilic substitution reactions using hydroxide ions (OH-), cyanide ions (CN-) and ammonia (NH3) as nucleophiles.
Elimination reactions Discussion on elimination and nucleophilic substitution reactions of halogenalkanes. Examples given of elimination reactions and the products produced by these reactions.

Organic Chemistry - Alcohols

Fermentation, biofuels and direct hydration Outline of how alcohol is made by fermentation and the pros and cons of biofuels is discussed. Finally the production of ethanol by direct hydration is contrasted with fermentation.
Reactions of alcohols Brief discussion of the reactions of alcohols, this includes products of combustion and the reactions of alcohols with metals such as sodium.
Oxidation of alcohols Explanation of the differences between primary, secondary and tertiary alcohols and the products of the oxidation of each class of alcohol.
Dehydration of alcohols Discussion of the elimination mechanism for the dehydration of alcohols to form alkenes..
Halogenalkanes from alcohols Discussion on how to prepare halogenalkanes from primary, secondary and tertiary alcohols. An experimental method is outlined for the formation of a tertiary halogenalkane from a tertiary alcohol.