Class 11 Chemistry Structure of Atom Heisenberg uncertainty principle

Heisenberg uncertainty principle                             



According to Heisenberg ,it is impossible to measure both the position and momentum of moving particle with accuracy.

  • If value of position is small ,it can be measured accurately but not momentum.
  • If value of momentum is small it is measured accurately but not the position.

Mathematically that means:



  • Suppose we need to measure position accurately, than we need to use light.
  • So, that the photon of light must strike the electron and reflected photon is seen with microscope.
  • Due to hitting, the position and velocity of electron is changed.
  • But to pin point position, the light of shorter wavelength should be used.
  • The shorter wavelength means high frequency and high energy.
  • So, this high energy photon may change the speed and direction of particle.



This holds good only for microscopic particles, as energy of photon is not enough to change the position and velocity of bigger bodies. So, in our daily routine it has no significance.       

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