AQA GCSE Chemistry Paper 1 Overview

Applicable for:

• Higher and Foundation Tier
• Double Combined Trilogy
• Triple Separate Chemistry

Topics Covered:

1. Atoms
2. Bonding
3. Quantitative Chemistry
4. Chemical Changes
5. Energy Changes

1. Atoms and the Periodic Table

• Atoms and Elements: Basic units represented by symbols on the periodic table.
• Compounds: Made of two or more different atoms chemically bonded (e.g., H₂O).
• Chemical Reactions: Represented with word and symbol equations. Atoms are conserved (not created or destroyed), requiring balanced chemical equations.
• Mixtures: Combination of elements and compounds not chemically bonded (e.g., air, solutions).
• Separation Techniques: Filtration, Crystallization, Distillation (including Fractional Distillation).
• States of Matter: Solid, liquid, and gas; changes involve energy but no new substances are formed.

Atom Models History

• JJ Thompson: Plum pudding model.
• Ernest Rutherford: Discovered nucleus.
• Niels Bohr: Electrons in shells.
• James Chadwick: Neutrons in nucleus.

Periodic Table Insights

• Atomic Number: Number of protons.
• Mass Number: Protons + Neutrons.
• Isotopes: Atoms with the same number of protons but different neutrons.
• Group Trends: Similar properties in columns, reactivity trends down groups.

2. Bonding

• Metallic Bonding: Lattice of ions with delocalized electrons; good conductors.
• Ionic Bonding: Between metals and non-metals; involves transfer of electrons.
• Covalent Bonding: Sharing of electrons between non-metals.
• Structure Types:
  • Simple Molecular Structures: Low boiling points, non-conductive.
  • Giant Covalent Structures: High melting points, examples include diamond and graphite.

Special Structures

• Graphite: Layers, conducts electricity.
• Fullerenes: Spherical and tubular carbon structures.

Triple Chemistry Only

• Nanoparticles: Large surface area to volume ratio; implications in material use.

3. Quantitative Chemistry

• Conservation of Mass: Total mass of reactants equals total mass of products.
• Moles Concept: Amounts compared using the mole; calculations with moles and mass.
• Stoichiometry: Ratios in chemical equations guide calculations; limiting reactants.
• Concentration of Solutions: From G/dm³ to mol/dm³.

Triple Only

• Percentage Yield & Atom Economy: Efficiency of reactions; important in industrial chemistry.

4. Chemical Changes

• Reactivity Series: Predicts reactions, extraction of metals.
• Displacement Reactions: More reactive metals displace less reactive metals from compounds.
• Oxidation and Reduction: Oil rig mnemonic (Oxidation is loss, Reduction is gain of electrons).
• Acid-Base Reactions: Neutralization forms salts and water.
• pH Scale: Logarithmic; measures H⁺ ion concentration.

Triple Only

• Titrations: Measuring concentrations of acidic or alkaline solutions.

5. Energy Changes

• Exothermic and Endothermic Reactions: Energy transfer in chemical reactions; temperature changes.
• Energy Profiles: Visual representations of energy changes, activation energy.
• Bond Energies: Calculations based on specific bond energies.

Triple Only

• Batteries and Fuel Cells: Chemical reactions that generate electricity.