CIE A Level Physics复习笔记23.1.2 Nuclear Equations
Representing Simple Nuclear Reactions Nuclear reactions can be represented by balanced equations of nuclei in the AZX form AZX notation for atomic nuclei The top number A represents the nucleon num...
CIE A Level Physics复习笔记23.1.1 Energy & Mass Equivalence
Energy & Mass Equivalence Einstein showed in his theory of relativity that matter can be considered a form of energy and hence, he proposed: Mass can be converted into energy Energy can be conv...
CIE A Level Physics复习笔记22.3.3 Calculating Discrete Energies
Calculating Discrete Energies The difference between two energy levels is equal to a specific photon energy The energy (hf) of the photon is given by: ΔE = hf = E2 - E1 Where, E1 = Energy of the hi...
CIE A Level Physics复习笔记22.3.2 Line Spectra
Line Spectra Line spectra is a phenomenon which occurs when excited atoms emit light of certain wavelengths which correspond to different colours The emitted light can be observed as a series of co...
CIE A Level Physics复习笔记22.3.1 Atomic Energy Levels
Atomic Energy Levels Electrons in an atom can have only certain specific energies These energies are called electron energy levels They can be represented as a series of stacked horizontal lines in...
CIE A Level Physics复习笔记22.2.2 The de Broglie Wavelength
The de Broglie Wavelength De Broglie proposed that electrons travel through space as a wave This would explain why they can exhibit behaviour such as diffraction He therefore suggested that electro...
CIE A Level Physics复习笔记22.2.1 Wave-Particle Duality
Wave-Particle Duality Light waves can behave like particles, i.e. photons, and waves This phenomenon is called the wave-particle nature of light or wave-particle duality Light interacts with matter...
CIE A Level Physics复习笔记22.1.5 The Work Function
Photoelectric Emission The work function Φ, or threshold energy, of a material is defined as: The minimum energy required to release a photoelectron from the surface of a material Consider the elec...
CIE A Level Physics复习笔记22.1.4 Threshold Frequency
Threshold Frequency & Wavelength The concept of a threshold frequency is required in order to explain why a low frequency source, such as a filament lamp, was unable to liberate any electrons i...
CIE A Level Physics复习笔记22.1.3 The Photoelectric Effect: Basics
The Photoelectric Effect: Basics The photoelectric effect is the phenomena in which electrons are emitted from the surface of a metal upon the absorption of electromagnetic radiation Electrons remo...
CIE A Level Physics复习笔记22.1.2 The Electronvolt
The Electronvolt The electronvolt is a unit which is commonly used to express very small energies This is because quantum energies tend to be much smaller than 1 Joule The electronvolt is derived f...
CIE A Level Physics复习笔记22.1.1 The Photon
The Particle Nature of Light In classical wave theory, electromagnetic (EM) radiation is assumed to behave as a wave This is demonstrated by the fact EM radiation exhibits phenomena such as diffrac...
