IGCSE Chemistry notes

Chemistry starts with the atom. This unit sets out the particles inside atoms, the difference between elements, compounds and mixtures, and how to describe them for IGCSE.

The kinetic particle model explains why solids, liquids and gases behave differently — and lets you predict what happens when we heat, cool or mix substances.

The properties of any substance come from the bonding between its particles. IGCSE focuses on three types of bonding and the structures they form.

Stoichiometry is the arithmetic of chemistry — using balanced equations and moles to work out how much of each substance reacts or is made.

The periodic table organises elements by proton number. Elements in the same group have similar properties because they have the same number of outer electrons.

Acids donate H⁺ ions; bases accept them. Combining them neutralises to give a salt and water. Salt preparation is a classic IGCSE practical.

How a metal is extracted depends on its position in the reactivity series. Reactive metals need electrolysis; less reactive metals are reduced by carbon.

Rates of reaction are all about how often particles collide with enough energy. Reversible reactions can reach a dynamic equilibrium where forward and backward rates are equal.

Organic chemistry is the chemistry of carbon compounds. Most start life in crude oil and are used as fuels, plastics and chemicals.

This unit connects chemistry to everyday life — the air we breathe, the water we drink, the fuels we burn and the impact on our environment.