Quantum Theory - created from Mind Map

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Wave-Particle Duality

De Broglie's Hypothesis

Planck's Theory

Photoelectric effect

An object at any temperature can emit electromagnetic radiation

Black body: an object that absorb all wavelength on it and reflecting none

Spectrum of radiation depends on temperature and properties of the object

From Stefan-Boltzmann Law, P=δeAT^4

δ= Stefan’s constant = 5.6703 x 10-8 watt/m2 K4 e= emissivity A= radiating area T= temperature

De Broglie’s hypothesis: light is considered as particle called photon which has mass and momentum

From Einstein’s mass-energy/photoelectric equation, mc^2=hc/λ

λ=h/mv

Planck’s theory: describe that waves can exhibit particle-like characteristic and particles can exhibit wave-like characteristic

Radiation energy, E=hf

h= Planck’s constant

= 6.626 x 10-34 J sf= frequency

From f=c/λ ,

E=hc/λ

c= 3.0 x 10^8 m s-1 λ= wavelength

From the energy conservation, E=W+Kmax

When electron absorbed photon energy, it overcome the bounding barrier and release itself from the metal surface, and the accelerated by the electric fields

The cut-off potential is corresponding to the maximum kinetic energy of electrons,

When monochromatic light fell on the cathode, photons weren’t emitted unless the frequency of light was greater than threshold frequency, f0

hf=hf0+Kmax

Kmax=eVs=1/2mvmax^2