CH1012
L1 /
‹#›
L1 /
2
ATOMIC STRUCTURE
Wave particle / duality
ATOMIC
STRUCTURE
Light has both wave and
particle properties.
Light travels as photons
eg. photoelectric effect
Light travels as photons
eg. photoelectric effect
Light of high enough
frequency
(to exceed Ethreshold)
(to exceed Ethreshold)
photoelectron
emitted
E µ frequency (particle theory)
not amplitude (wave theory)
not amplitude (wave theory)
and yet it diffracts readily (wave).
The electron also has both particle (cathode
rays) and wave properties (eg. diffraction).
rays) and wave properties (eg. diffraction).
Cathode
Ray Tube
Electron
beam
Visible light has Wave properties:
Wavelength l (nm) and frequency n (s-1 = Hz)
Wavelength l (nm) and frequency n (s-1 = Hz)
EM radiation in vacuum has speed c (c = l n)
E = h n energy is proportional to n (Greek nu)
h = 6.63 x 10-34 J s Plank’s constant
c = 3.00 x 108 m/s Speeed of light
h = 6.63 x 10-34 J s Plank’s constant
c = 3.00 x 108 m/s Speeed of light
