Unit 1 tests fundamental physical and inorganic principles that underpin all higher-level chemical reasoning. Questions assess theoretical understanding, mathematical problem-solving, and practical laboratory techniques tested in written context.
Unit 1 is examined in both the January series and the May/June series. Candidates can sit Unit 1 in January of Year 12 as an early benchmark, with the full freedom to resit in May/June to bank the highest score.
Marks achieved in Unit 1 can be cashed in alongside Unit 2 for the standalone International AS award (code 9621), or carried forward within the shelf-life of the specification towards the full International A-Level award (code 9622).
Select any module below to access comprehensive revision notes, mathematical derivations, worked examples, and interactive practice questions:
Subatomic particles, isotopes, TOF mass spectrometry, relative atomic mass from mass spectra, electron configurations (Cr and Cu anomalies), and first and successive ionisation energies.
Open Topic Notes →Relative atomic and molecular mass, the mole and the Avogadro constant, n = m/M and n = cV, the ideal gas equation pV = nRT, and empirical and molecular formulas.
Open Topic Notes →Balancing full and ionic equations, reacting masses, gas volumes, percentage yield, atom economy, and titration calculations with the RP1 method and back titrations.
Open Topic Notes →Ionic, covalent, coordinate (dative), and metallic bonding; electronegativity and intermolecular forces (hydrogen bonding in ice and water); VSEPR shapes and angles.
Open Topic Notes →Standard enthalpy definitions (formation, combustion), calorimetry q = mc ΔT, cooling curve extrapolation, Hess Law cycles, and mean bond enthalpies.
Open Topic Notes →Oxidation and reduction as electron transfer, oxidising and reducing agents, rules for oxidation states, half-equations in acid, and combining them into overall redox equations.
Open Topic Notes →Period 3 element trends from Na to Ar, nuclear charge vs shielding, atomic radius contraction, first ionisation energy pattern, and structural melting point variations.
Open Topic Notes →Reactivity with water and steam, opposing hydroxide and sulfate solubility trends, medical applications (barium meal, antacids), titanium extraction, and flue gas desulfurisation.
Open Topic Notes →Electronegativity and boiling point trends, redox displacement reactions, solid halide reactions with concentrated sulfuric acid, silver nitrate tests with ammonia, and chlorine disproportionation.
Open Topic Notes →Full written paper (70 marks) with AI marking, plus 15 warm-up multiple-choice questions.
Launch Practice Exam (70 Marks) →