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Principles of chemistry
States of matter
1.1-1.3 - Particle model and changes of stateChemists explain solids, liquids and gases by looking at what their particles are doing. The same substance can change state when energy is transferred, but its particles are still the same kind of particles. This lesson links the particle model to the names of changes of state, dilution of colou...
1.4-1.7C - Solutions, solubility curves and solubility practicalA solution forms when one substance dissolves in another. In this lesson, you will learn the exact language for solutions, how solubility is measured in g per 100 g of solvent, how to read and draw solubility curves, and how the Edexcel solubility practical turns mass readings into a solubility v...
Elements, compounds and mixtures
1.8-1.9 - Elements, compounds, mixtures and purityChemists classify materials by what particles are present and whether those particles are chemically joined. This lesson builds the three key labels, element, compound and mixture, then uses melting and boiling point data to decide whether a substance is pure. The exam skill is not just naming th...
1.10-1.13 - Separation techniques and chromatographyMixtures can be separated because their substances keep their own physical properties. In this lesson, you will choose and describe the separation techniques named in the Edexcel IGCSE Chemistry specification, then use chromatograms and Rf values to identify dyes in inks or food colourings. The k...
The Periodic Table
1.18-1.19, 1.22 - Periodic table arrangement and electron configurationsThe Periodic Table is not just a list of elements. Its rows and columns give clues about atomic number and electron arrangement. In this lesson, you will learn how to use an element's position to deduce its electronic configuration for the first 20 elements.
1.20-1.21 - Metals and non-metalsChemists often begin by asking a simple classification question: is this element a metal or a non-metal? In this lesson, you will use three kinds of evidence: where the element sits in the Periodic Table, whether the element conducts electricity, and whether its oxide behaves as acidic or basic.
1.23-1.24 - Group trends and noble gasesThe Periodic Table is not just a list of elements: it puts elements with related electron arrangements into the same vertical groups. This lesson explains why elements in the same group often react in similar ways, and why the noble gases in Group 0 are different because their outer shells are al...
Chemical formulae, equations and calculations
1.25-1.26 - Writing equations and calculating formula massesChemical equations are a compact way to show what changes during a reaction. This lesson teaches how to move from words to balanced chemical equations with state symbols, and how to calculate relative formula mass, Mr, from relative atomic masses, Ar. The same careful counting links both skills:...
1.27-1.30 - Moles, reacting masses and percentage yieldChemists cannot count atoms or ions one by one, so they use a counting unit called the mole. In this lesson, you will use masses, relative atomic masses, relative formula masses and balanced equations to work out how much substance reacts or forms. You will then compare the maximum possible produ...
1.31-1.33 - Empirical and molecular formulae from dataA chemical formula tells you the ratio of atoms or ions in a substance. This lesson shows how experimental mass data can be turned into that ratio, and how an empirical formula can be scaled up to a molecular formula when the Mr is known. The central move is always the same: change masses into mo...
1.34C-1.35C - Concentration and gas volume calculationsChemists often measure a volume in the lab, but balanced equations compare amounts of substance in moles. In this lesson, the same idea appears twice: a solution volume can be linked to concentration, and a gas volume can be linked to the molar volume of a gas at room temperature and pressure. Th...
1.36 - Formula of a metal oxide practicalA metal oxide contains a metal chemically combined with oxygen. In this practical, the formula is found from mass measurements: either oxygen is added to a metal by combustion, or oxygen is removed from a metal oxide by reduction. The skill is not just doing the heating; it is using the mass chan...
Ionic bonding
1.37-1.39 - Ions, charges and ionic formulaeIonic formulae are built from charged particles called ions. In this lesson you will learn how atoms become ions, which ion charges Edexcel expects you to know, and how to combine those charges to write formulae such as $MgCl2$ and $(NH4)2CO3$.
1.40-1.43 - Ionic bonding and giant ionic lattice propertiesIonic compounds form when electrons are transferred from metal atoms to non-metal atoms. The oppositely charged ions produced are held together by electrostatic attractions in a giant repeating lattice, and that structure explains their melting points and electrical conductivity.
Covalent bonding
Metallic bonding
Electrolysis
Inorganic chemistry
Group 1 (alkali metals) - lithium, sodium and potassium
Group 7 (halogens) - chlorine, bromine and iodine
Gases in the atmosphere
Reactivity series
Extraction and uses of metals
Acids, alkalis and titrations
Acids, bases and salt preparations
Chemical tests
Physical chemistry
Energetics
Rates of reaction
Reversible reactions and equilibria
Organic chemistry
Introduction
Crude oil
Alkanes
Alkenes
Alcohols
Carboxylic acids
Esters
Synthetic polymers