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SUBJECT-CHEMISTRY

CHAPTER-ATOMIC STRUCTURE

SUBTOPIC- Dual nature of matter(de Broglie concept) and Heisenberg

uncertainty principle.

KEY NOTES:

 Dual nature of matter(de Broglie concept)
According to Einstein light has dual nature, i.e., wave nature as well as
particle nature. But Louis de Broglie all material particles such as

electron, proton, atoms, molecules, a piece of chalk or stone or an iron
ball also possess dual character.

 The wave associated with a particle is called a matter wave or de
h
Broglie wave, i.e.  
mv
Where h= Planck's constant

m = mass of the object
v = velocity of particle

 DERIVATION :
In case of a photon according to Planck's quantum theory

E  h  ………………………………….(1)
According to Einstein

E  mc …………………………………..(2)
2
Comparing these two equations we have
h  mc

2
c
But we know that  


Putting this value in above equation we have

c
h  mc 2

h
 
mc