Chapter 13 - Quantum Physics Flashcards
Quantum
The smallest, indivisible amount of a physical quantity
Quantised
A physical quantity whose magnitude is limited to a set of discrete values
Photon
A quantum of electromagnetic energy
Energy of a photon equation
E = hf
Planck's constant x frequency
hc
or E = ------
λPlanck’s constant
6.63 x 10^-34 Js
Electron volt
eV - 1.6 x 10^-19 J
Electron volt definition
The work done to move an electron through 1V of potential difference
Threshold frequency (f0)
The minimum frequency of light required for electrons to be emitted in photoelectric emission, it is dependent on the work function of a metal
Effect of changing the light intensity on thermionic emission
Increasing the light intensity allows for more electrons to be emitted as long as f > f0
Effect of changing the frequency on thermionic emission
As long as f > f0, the electrons emitted will have more kinetic energy
Work function (Φ)
The minimum energy required to remove an electron from the surface of the metal
Electrons to photons in photoelectric emission
Electrons absorb energy from photons in a 1:1 ratio
Photoelectric effect equation
hf = Φ + Ekmax
Threshold frequency equation
f0 = Φ/h
de Broglie’s theorem
Any moving particle or object has an associated wave
