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Overview of AQA GCSE Chemistry Paper 1

Mar 13, 2025

AQA GCSE Chemistry Paper 1 Overview

Content Overview:

  • The video covers all topics in AQA GCSE Chemistry Paper 1 aimed at a Grade 9 standard.
  • Includes sections on atomic structure, periodic table, chemical reactions, and more.
  • Predicted papers and walkthroughs are available for practice.

Note-taking Strategy:

  • Separate science content will be indicated.
  • Watch at preferred speed but take notes and practice questions.

Atomic Structure

Definition of an Atom

  • Smallest part of an element.
  • Represented by a chemical symbol (e.g., O for Oxygen).

Size of an Atom

  • Radius: ~0.1 nanometers (1 * 10^-10 m).
  • Nucleus radius: less than 1/10,000 of the atom.*

Elements and Compounds

  • Element: Substance made of one type of atom.
  • Compound: Substance made of two or more elements chemically combined.
  • Properties differ from constituent elements.

Separation of Compounds

  • Can only be achieved through chemical reactions.
  • Energy changes often involved.

Chemical Reactions

  • Formation of new substances with energy changes.

Chemical Equations

Word and Symbol Equations

  • Word equations: Water → Hydrogen + Oxygen.
  • Symbol equations: H2O → H2 + O2 (must be balanced).

Balancing Equations

  • Ensure equal numbers of each atom on both sides.
  • Balance using coefficients (e.g., 2H2O → 2H2 + O2).

Common Formulas to Remember

  • CO2, H2O, O2, H2, N2, NH3, HCl, H2SO4.

Subatomic Particles

Types of Particles

  • Protons (+1 charge, mass = 1).
  • Neutrons (0 charge, mass = 1).
  • Electrons (-1 charge, very small mass).

Isotopes

  • Atoms with same protons but different neutrons.

Ions

  • Charged particles formed by loss/gain of electrons.

Electron Shells

Arrangement

  • Electrons fill from inner to outer shells.
  • 1st shell: 2 electrons, 2nd & 3rd shell: 8 electrons.

Periodic Table Representation

  • Mass number = protons + neutrons.
  • Atomic number = protons.

Mixtures and Separation Techniques

Mixtures

  • Combination of elements/compounds not chemically combined.

Separation Methods

  • Filtration, Crystallization, Distillation.
  • Chromatography for colored compounds.

History of Atomic Model Development

Key Models and Discoveries

  • Dalton’s solid sphere, Thomson’s Plum Pudding, Rutherford’s Nuclear model.
  • Chadwick’s discovery of neutrons.

Periodic Table

Structure

  • Groups (columns) and Periods (rows).
  • Similar properties within groups.

Reactivity Series

  • Metals vs. Non-metals.
  • Group 0: Noble gases, unreactive.
  • Group 1: Alkali metals, reactivity increases down the group.

Chemical Bonding

Types of Bonds

  • Ionic (metal + non-metal), Covalent (non-metal), Metallic (metals).

Ionic Compounds

  • Formed by electron transfer, electrostatic attraction.
  • High melting/boiling points, conduct electricity in liquid form.

Covalent Compounds

  • Shared electrons, form molecules (e.g., H2O, CO2).
  • Low melting/boiling points, don’t conduct electricity.

Giant Covalent Structures

  • Diamond, graphite (conducts electricity), silicon dioxide.

Metals and Alloys

Metal Structure

  • Malleable, high melting points.

Alloys

  • Mixture of metals, harder than pure metals.

Nanoparticles

Properties

  • Large surface area to volume ratio.

Uses

  • Medicine, Electronics, Catalysts.

Risks

  • Can enter cells, catalyze harmful reactions.

Conservation of Mass and Calculations

Key Concepts

  • Mass conserved in reactions.
  • Relative formula mass and its calculations.
  • Percentage composition by mass in compounds.

Moles and Calculations

  • Avogadro’s constant (6.02 * 10^23).
  • Calculating mass, moles, and concentrations.*

Chemical Reactions

Types of Reactions

  • Oxidation, Reduction, Displacement.

Reactions with Acids

  • Metal + Acid → Salt + Hydrogen.
  • Neutralization reactions.

Making Salts

  • From acids and bases.

Acids and Bases

Acids in Solution

  • Produce H+ ions.

Bases

  • Produce OH- ions.

pH Scale

  • Measures acidity/alkalinity.

Titrations

  • Used to find concentrations.

Electrolysis

Basics

  • Splitting compounds using electricity.

Electrolysis of Solutions

  • Products depend on reactivity and ions present.

Extraction of Metals

  • Using electrolysis (e.g., aluminium).

Energy Changes

Exothermic vs Endothermic Reactions

  • Exothermic: Energy released to surroundings.
  • Endothermic: Energy absorbed from surroundings.

Bond Energies

  • Calculating overall energy change in reactions.

Cells and Batteries

Chemical Cells

  • Produce electricity using chemicals.

Fuel Cells

  • Hydrogen fuel cells, advantages, and disadvantages.