index heading

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.

Home page


Atomic structure and the mass spectrometer

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 Thompson and Rutherford on the helping to develop 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.
Time of flight mass spectrometer (TOF) Overview to the workings of a time of flight mass spectrometer - AQA exam board only.
The mass spectrometer Overview of the workings of a single beam mass spectrometer.
Mass spectra Introduction to mass spectra and how to calculate relative atomic mass of isotopes. Examples of the mass spectra for the element boron and chlorine

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 covers: Line spectra, Planck and quantised energy, the photoelectric effect and the Pauli exclusion principle. Schrodinger wave equations are also introduced.
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.

Bonding

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 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

Intermolecular bonding and dipole-dipole interactions Introduction to intermolecular bonding and dipole-dipole interactions.
Van der Waals bonding Explanation with examples on how Van der Waals forces (London dispersion forces) originate and their effects on the physical properties of substances.
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.

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.

Energetics

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 permanaganate as oxidising agents in redox reactions. Help given on how to deal with complex redox equations with example problems and answers provided.

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 halogens 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 reaction using the reactions of chlorine with water and sodium hydroxide as examples.