AQA GCSE Chemistry Paper 1 Revision Notes

Introduction

• Covers topics: Atoms, Bonding, Quantitative Chemistry, Chemical and Energy Changes.
• Relevant for Higher and Foundation Tiers, Double Combined Trilogy, and Triple Separate Chemistry.

Atoms and Elements

• Atoms: Basic unit of matter, represented by symbols in the periodic table.
• Elements: Types of atoms; each element has a unique symbol.
• Compounds: Substances with two or more elements chemically bonded, e.g., H₂O.
• Mixtures: Combination of substances not chemically bonded, e.g., air, saltwater.

Chemical Reactions and Equations

• Chemical Reactions: Atoms rearrange, represented by word and chemical equations.
• Balancing Equations: Ensure equal number of each atom on both sides.
• Physical Separation: Filtration, crystallization, distillation (fractional included).

States of Matter

• Solid, Liquid, Gas: Differences in particle arrangement and energy.
• State Changes: Physical processes requiring energy, not chemical reactions.

Atomic Structure

• History: JJ Thompson, Ernest Rutherford, Niels Bohr, and James Chadwick’s contributions.
• Protons, Neutrons, Electrons: Protons and neutrons in nucleus, electrons in shells.
• Ions: Atoms that gain/lose electrons.

Periodic Table

• Structure: Atomic number, mass number, groups, and periods.
• Isotopes: Atoms with same number of protons, different neutrons.
• Dmitri Mendeleev: Developed early periodic table based on properties.

Bonding

• Metallic Bonds: Electrons shared in a lattice structure.
• Ionic Bonds: Metal donates electrons to non-metal.
• Covalent Bonds: Atoms share electrons.

Types of Chemical Bonds

• Simple Molecular Structures: Low melting points due to weak intermolecular forces.
• Giant Covalent Structures: High melting points, e.g., diamond and graphite.
• Metal Alloys: Stronger than pure metals due to mixed atomic sizes.

Quantitative Chemistry

• Conservation of Mass: Total mass of reactants = total mass of products.
• Moles: Measurement of substance amount; 1 mole = relative mass in grams.
• Concentration: Measured in g/dm³ or mol/dm³.

Chemical Changes

• Reactivity Series: Determines displacement reactions.
• Reduction and Oxidation (Redox): Oil Rig mnemonic; electrons transfer.
• Acid-Base Reactions: Neutralization produces salt and water.

Energy Changes in Reactions

• Exothermic vs Endothermic: Energy released vs absorbed.
• Energy Profiles: Visual representation of energy changes.
• Bond Energies: Calculate net energy change in reactions.

Electrolysis

• Process: Decomposition of substances using electricity.
• Purification: Extract metals from compounds.
• Applications: Electrolysis of solutions for different products.

Additional Topics for Triple Science

• Surface Area to Volume Ratio: Importance in reactions and nanotechnology.
• Titrations: Determine concentration of solutions.

Conclusion

• Covers important concepts and techniques for the Chemistry Paper 1 examination.
• Study effectively using these notes for a comprehensive understanding of the material.