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...
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...
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...
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...
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...
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...
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...
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...
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...
