What are isotopes?

Atoms of the same element may not be identical. The different forms of an element are called isotopes.

Distillation: an ancient technique to separate liquid

Distillation has been used to separate and purify liquid since more than 2000 years ago.

Proton: getting particular about identifying elements

The proton is the subatomic particle that defines the chemical identity of an element.

Electron: what we know and can never know

The electron is the first subatomic particle to be discovered, turning chemistry on its head more than a century ago.

Carbon dioxide & other acidic oxides

Some oxides can behave like an acid and neutralise bases. How do you identify them?

What is atomic structure?

The atom is not a featureless ball. It consists subatomic particles arranged in an mind-boggling way.

Kinetic particle theory

The kinetic particle theory explains the visible with the invisible.

Global warning: global warming

We can all play a part to clear the air of greenhouse gases to slow global warming.

What are cation and anion?

Have your eye on ion

Iron extraction and steelmaking

Ironing out how we get iron out of haematite

Reactivity series of metals

Memorise the reactivity series of metals without memorising

Metals and alloys: materials that changed history

Uncover the properties and reactivity of metals that matter to the story of humankind

Speeding up reactions with catalysts and enzymes

Catalyse your revision on catalysts and enzymes

5 ways to increase reaction speed

Speed read the five factors that influence reaction speed

How to find oxidation state?

Learn how to state the oxidation state

Redox reactions: oxidation and reduction

Four lenses for a new way to look at chemical reactions

Stoichiometry: percentage yield & percentage purity

Be 100% sure about how to calculate percentage yield and percentage purity

Enthalpy change of reactions

Exo is hot, endo-ure the cold

Preparation of salts

The three methods to prepare pure samples of solid salt