AQA GCSE Chemistry Paper 1 Overview

Relevant Tiers and Exams

• 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

Atoms and Compounds

• Atoms: Basic units represented in the periodic table.
• Compounds: Two or more different atoms chemically bonded (e.g., H₂O).
• Chemical Reactions: Change in bonding of atoms, represented by balanced equations.
• Mixtures: Combination of elements/compounds not chemically bonded.
  • Examples: Air (Oxygen + Nitrogen), Solutions (e.g., Saltwater).
  • Methods of Separation: Filtration, Crystallization, Distillation (including fractional).

States of Matter

• Solid, Liquid, Gas: Main states with different particle arrangements and energy levels.
• Physical Changes: Changes that do not make a new substance (e.g., melting, boiling).

Atomic Models and Structure

• Historical Models: Plum pudding, Rutherford’s nucleus discovery, Bohr's electron shells.
• Protons, Neutrons, Electrons: Charge and relative mass properties.
• Periodic Table: Atomic number (protons) and mass number (protons + neutrons).
• Isotopes: Same element, different neutron numbers.

Electron Configuration

• Shells: Maximum electrons per shell (2, 8, 8, 2).
• Metals vs. Non-metals: Electron donation vs. acceptance.
• Groups and Periods: Indicate electron configuration and similar properties.

Bonding Types

1. Metallic Bonding: Metals share delocalized electrons, good conductors.
2. Ionic Bonding: Metals donate electrons to non-metals (e.g., NaCl).
3. Covalent Bonding: Non-metals share electrons to form molecules (e.g., O₂).

Special Structures

• Giant Covalent Structures: Diamond, graphite.
• Allotropes of Carbon: Graphene, fullerenes, nanotubes.

Quantitative Chemistry

• Conservation of Mass: Atoms are neither created nor destroyed.
• Moles: Measure of substance amount; formula: moles = mass / RAM.
• Concentration: Expressed in g/dm³ or mol/dm³.

Chemical Changes

• Reactivity Series: Determines reactions (e.g., displacement, extraction).
• Redox Reactions: Oxidation is loss, reduction is gain (OIL RIG).
• Neutralization: Acid + Alkali = Salt + Water.
• pH Scale: Logarithmic scale measuring acidity/alkalinity.

Energy Changes

• Exothermic Reactions: Energy released (e.g., combustion).
• Endothermic Reactions: Energy absorbed.
• Energy Profiles: Show energy changes during reactions.

Electrolysis

• Process: Decomposition of ions by electric current.
• Electrodes: Cathode (reduction), Anode (oxidation).

Additional for Triple Science

• Surface Area to Volume Ratio: Importance in nanoparticles.
• Percentage Yield and Atom Economy: Measure efficiency of reactions.
• Titrations: Method to determine concentration of solutions.
• Fuel Cells: Use hydrogen to produce electricity and water as a by-product.

Conclusion

• Review the topics and focus on understanding core concepts and calculations.
• Use the periodic table and equations effectively in problem-solving.