2.7 Photons Flashcards
(27 cards)
What is a Photon
Discrete packets of energy representing light.
What is the Photoelectric Effect
Ejection of electrons when light hits a material.
What is the Gold Leaf Electroscope
Device to demonstrate the photoelectric effect.
What is Work Function (ϕ)
Minimum energy needed to eject electrons.
What is Threshold Frequency (fT)
Minimum frequency for electron emission to occur.
What is Maximum Kinetic Energy (Ekmax)
Energy of ejected electrons after overcoming work function.
What is Stopping Voltage (V)
Voltage at which no current flows in circuit.
What is Vacuum Photocell
Device measuring maximum kinetic energy of electrons.
What is Electrostatic Repulsion
Force opposing electron movement towards collector.
What is the Electromagnetic Spectrum
Range of all types of electromagnetic radiation.
What is the Visible Light Range
Wavelengths from 400nm (violet) to 700nm (red).
What is the Emission Spectrum
Light spectrum emitted by excited atoms.
What is the Absorption Spectrum
Spectrum showing absorbed wavelengths by atoms.
What is Energy Level Diagram
Visual representation of electron energy states.
What is Ionisation Energy
Energy required to remove an electron from an atom.
What is Electron Diffraction
Wave-like behavior of electrons producing diffraction patterns.
What is De Broglie Wavelength
Wavelength associated with a particle’s momentum.
What is Radiation Pressure
Pressure exerted by electromagnetic radiation on surfaces.
What is Momentum Change (Δp)
Difference in momentum before and after photon reflection.
What is Force Calculation
Force equals rate of change of momentum.
What is Photon Energy Formula
E = hf, where E is energy, h is Planck’s constant.
What is the Kinetic Energy Formula for ejected electrons
Ek = hf - ϕ, for ejected electrons.
What is Photon Frequency (f)
Number of wave cycles per second of light.
What is Photon Wavelength (λ)
Distance between successive peaks of a light wave.
