Related: Past Papers Topical Questions IGCSE Physics AS Chemistry Grade Boundaries Command Words

2. Atoms, Elements & Compounds

Cambridge IGCSE Chemistry (0620) · 13 topics

Elements, Compounds & Mixtures

Elements, Compounds and Mixtures All matter can be classified as either a pure substance (an element or a compound) or a mixture . Element: a substance made of…
Atomic Structure

The Structure of the Atom An atom has a small, dense nucleus containing protons and neutrons, surrounded by electrons arranged in shells. Particle Location…
Electronic Configuration

Filling Electron Shells Electrons occupy shells (energy levels) around the nucleus, filling the innermost shell first. 1st shell: maximum 2 electrons 2nd shell:…
Isotopes

What are Isotopes? Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons - so they share the same atomic…
Ions & Ionic Bonds

Forming Ions Atoms can gain or lose electrons to become charged particles called ions , achieving a stable, full outer shell like the nearest noble gas. Cation…
Ionic Bonds & Lattice Structure

The Giant Ionic Lattice Ionic compounds do not exist as separate pairs of ions or as individual "molecules". Instead, ions pack together into a giant ionic…
Properties of Ionic Compounds

High Melting and Boiling Points Ionic compounds typically have high melting and boiling points (e.g. NaCl: 801°C, MgO: 2852°C). The giant lattice is held…
Covalent Bonds

What is a Covalent Bond? A covalent bond forms when a pair of electrons is shared between two atoms, so that both atoms gain a stable, noble-gas electronic…
Molecules & Compounds

What is a Molecule? A molecule is a group of two or more atoms held together by covalent bonds. A molecule can be a molecular element (only one type of atom,…
Properties of Simple Molecular Compounds

Two Different Forces Simple molecular substances have two very different types of force acting on them, and it is essential not to confuse the two: Covalent…
Diamond & Graphite

Giant Covalent Structures Diamond and graphite are both allotropes of carbon - different structural forms of the same element in the same physical state. Both…
Silicon(IV) Oxide

Structure of Silicon(IV) Oxide Silicon(IV) oxide (silicon dioxide, SiO₂) is the main component of sand and quartz. Like diamond, it has a giant covalent…
Metallic Bonding

What is Metallic Bonding? Metallic bonding is the electrostatic attraction between the positive ions in a giant metallic lattice and a "sea" of delocalized…