CHAPTER - ATOMIC STRUCTURE

Dr. Anil Kumar Soni
Assistant Professor (Level-
12)
Department of Chemistry,
Shia Post Graduate
College,
Luck now-226020

, UNIT-I
“ATOMIC STRUCTURE”

“Quantum mechanics-based structure of
atom”
“De-Broglie’s concept of matter waves”-(Dual nature of Matter or
electron/wave-particle nature of matter)
 According to Max Plank’s quantum theory of radiation, some phenomenon
like photoelectric effect and black body radiation can be explained on the
basis of particle nature of light.
 According to Maxwell’s theory of radiation, other phenomena like diffraction,
interference and polarization can be explained on the basis of wave nature of
light.
 Thus we can say light behave both as particle and as a wave.
 In 1924 a French physicist, . Louis de Broglie extended the idea of dual
character of light to matter particles and suggested that all matter particle
in motion(e.g. electron, proton, neutron , atoms or molecules etc.) have a
dual character, i.e. all matter particles possess characterstics of both a
material particle and a wave.

,  The wave associated with matter particle is called de Broglie matter wave.
 The idea of de Broglie is called Dual nature of matter.
 According to “de-Broglie” an electron behave both as material
particle and as a wave.
De-Broglie equation
 According to “de Broglie”, the momentum of a moving electron or
particle is inversely proportional to its wavelength.



[Since P =
m.v]



Here, h = Plank’s constant (6.626x10-34 J.s)
λ = wavelength of wave
m = mass of electron
v = velocity of electron