Periodic Trends
What You Will Learn: Periodic Trends · Organisation of the Periodic Table · Atomic Radius, Ionic Radius, and Electronegativity Trends
IB Chemistry topic guide
Structure 3: Classification of Matter
Structure 3: Classification of Matter is a core part of IB Chemistry. This guide connects the syllabus ideas behind Periodic Trends, Group Chemistry, Introduction to Organic Chemistry, Isomerism and IUPAC Nomenclature, shows how they appear in worked problems, and points you to the formulas and full lessons needed for exam revision.
What you will learn
Structure 3: Classification of Matter syllabus outline
The units below follow the structure used in the full Study to Learn course. Use the outline to identify exactly which idea needs attention, then work through the public example before continuing to the complete lesson path.
Group Chemistry
What You Will Learn: Group Chemistry · Alkali Metals and Halogens · Period 3 Oxides and Chlorides: Bonding and Acid–Base Character
Introduction to Organic Chemistry
What You Will Learn: Introduction to Organic Chemistry · Organic Compounds and Homologous Series · Functional Groups and Structural Representation
Isomerism and IUPAC Nomenclature
What You Will Learn: Isomerism and IUPAC Nomenclature · Structural Isomerism · IUPAC Nomenclature: Systematic Naming
Free worked preview
What You Will Learn: Periodic Trends
This complete preview comes from the Periodic Trends unit. It introduces the core language, shows the method in context, and gives you a real example of the lesson quality before you create an account.
What You Will Learn: Periodic Trends
Section C classifies matter, and this opening topic returns to the periodic table — first introduced through electron configuration in A3 — to show how its organisation predicts element properties without memorisation. The first lesson recaps how the table is built from groups, periods, and blocks. The second lesson then teaches the three core periodic trends: atomic radius, ionic radius, and electronegativity, all explained through the same underlying factors of nuclear charge and shielding you met when studying ionisation energy in A3.2.
What You'll Cover
- How the periodic table is organised into groups, periods, and blocks, and what this organisation reveals about element properties.
- Trends in atomic radius, ionic radius, and electronegativity across periods and down groups, explained through nuclear charge and shielding.
By the end of this topic you will be able to predict and explain how a chosen property changes between any two elements based purely on their position in the table.
Reviewed by the Study to Learn editorial team · Updated 2026-08-04