← Chemistry syllabus

WalesChemistry

Unit 1: The Language of Chemistry, Structure and Physical Chemistry

7 dot points across 7 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

What are atoms made of and how are their electrons arranged?

Sub-atomic particles, isotopes, mass spectrometry and relative atomic mass, electron configurations in s, p and d sub-shells, and successive ionisation energies.
A focused answer to WJEC A-Level Chemistry Unit 1, covering sub-atomic particles, isotopes, the time-of-flight mass spectrometer, relative atomic mass, electron configurations in s, p and d sub-shells, and the evidence from successive ionisation energies.
12 min answer →

How are atoms held together and what shapes do molecules take?

Ionic, covalent, dative and metallic bonding, electronegativity and polarity, intermolecular forces, and the shapes of simple molecules from electron-pair repulsion.
A focused answer to WJEC A-Level Chemistry Unit 1, covering ionic, covalent, dative and metallic bonding, electronegativity and bond polarity, the three intermolecular forces, and predicting molecular shapes from electron-pair repulsion theory.
12 min answer →

How do we count atoms and quantify what happens in a reaction?

The mole, Avogadro constant, molar mass, concentration, the ideal gas equation, empirical and molecular formulae, and percentage yield and atom economy.
A focused answer to WJEC A-Level Chemistry Unit 1, covering the mole and Avogadro constant, molar mass, solution concentration, the ideal gas equation, empirical and molecular formulae, and yield and atom economy with worked stoichiometry.
12 min answer →

How do we write what happens in a chemical reaction?

Oxidation numbers, formulae of ionic and covalent compounds, writing and balancing full, ionic and half equations, and state symbols.
A focused answer to WJEC A-Level Chemistry Unit 1, covering oxidation numbers, deducing formulae of ionic and covalent compounds, writing and balancing full, ionic and redox half equations, and using state symbols correctly.
11 min answer →

What is dynamic equilibrium and how do acids and bases behave?

Dynamic equilibrium, Le Chatelier's principle, the Bronsted-Lowry model of acids and bases, strong and weak acids, and acid-base titrations.
A focused answer to WJEC A-Level Chemistry Unit 1, covering dynamic equilibrium, Le Chatelier's principle, the Bronsted-Lowry definition of acids and bases, strong versus weak acids, and acid-base titration calculations.
11 min answer →

How does the structure of a solid explain its properties?

Giant ionic, giant covalent, simple molecular and metallic structures, and how bonding and structure explain melting point, conductivity, hardness and solubility.
A focused answer to WJEC A-Level Chemistry Unit 1, covering giant ionic, giant covalent, simple molecular and metallic lattices, and how each structure explains melting point, electrical conductivity, hardness and solubility.
11 min answer →

How do properties of elements vary across the periodic table?

Periodicity of atomic radius, ionisation energy, melting point and electronegativity across Period 3, and trends in Group 2 and Group 7 chemistry.
A focused answer to WJEC A-Level Chemistry Unit 1, covering the periodicity of atomic radius, ionisation energy, melting point and electronegativity across Period 3, and the reactivity trends in Group 2 and Group 7.
11 min answer →