AQA GCSE Physics Paper 1: Key Topics Overview

Introduction

Covers topics 1 to 4: Energy, Electricity, Particles, and Atomic Structure (Nuclear Physics).
Applies to Higher, Foundation Tier, Double Combined Trilogy, and Triple/Separate Physics.

Conservation of Energy: Total energy in a system is conserved; energy cannot be created or destroyed.
Energy Stores:
- Kinetic Energy: ( E = \frac{1}{2} mv^2 )
- Gravitational Potential Energy (GPE): ( E = mgh )
- Elastic Potential Energy: ( E = \frac{1}{2} k e^2 )
- Thermal Energy: ( E = mc\Delta T )
Energy Transfer: Energy must be transferred for anything to happen in a system.
Power: Rate of energy transfer, ( P = \frac{E}{T} ).
Efficiency: Useful energy out / Total energy in.

Basic Concepts:
- Electricity is the flow of charge.
- Current (I) flows from positive to negative.
- Potential Difference (PD) measures energy transferred per coulomb.
Measuring Electricity:
- Voltmeter measures PD across components.
- Ammeter measures current.
Circuits:
- Series: PD is shared; current is the same; total resistance is the sum of individual resistances.
- Parallel: PD is the same; current is shared; adding resistors decreases total resistance.
Ohm's Law: ( V = IR ).
Components:
- Resistors, Diodes, Thermistors, Light Dependent Resistors (LDRs).

Density: ( \text{Density} = \frac{\text{mass}}{\text{volume}} ).
States of Matter: Solid, Liquid, Gas.
- Change of state involves energy transfer.
Internal Energy: Sum of kinetic and potential energy of particles.
Specific Heat Capacity: Energy to change the temperature of 1kg by 1°C.
Specific Latent Heat: Energy to change the state of 1kg without a temperature change.

Models of the Atom: Thomson, Rutherford, Bohr, Chadwick.
Isotopes: Atoms with same protons, different neutrons.
Radioactivity:
- Alpha Decay: Releases 2 protons, 2 neutrons.
- Beta Decay: Neutron turns into a proton, emits an electron.
- Gamma Radiation: Emission of energy without particles.
Half-life: Time for half of radioactive isotopes to decay.