Rutherford's scattering experiment and Nuclear Model of ATOM :

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Scattering of Alpha particles by thin metal foil :—


https://youtu.be/3b5pEBi69hc

The First Idea of atomic model was proposed by E. Rutherford (1911) which was based upon his novel experiment of scattering of Alpha particles by metal foil.

 an Alpha emitter was placed in a lead box. A narrow  beam of alpha particles escaped through small hole in the lead box and hit a thin metal foil of gold ( 0.0004 mm thickness) which was placed in the beam of the alpha particles. A circular fluorescent ( zinc sulphide )  screen was set up around the metal foil. A flash of light was observe when the alpha particles hit the screen after penetrating through the thin foil.  


Observation  :

(1.),  Most of the alpha particles (99.84 %)  passed straight through the foil without any deflection. 

(2.)  0.14 %  of alpha particles deviated more than   1°

(3.)  1 in 8000 alpha particles deviated more than 90°

(4.)    1 in 10⁶ alpha particles deviated about 180°

 

Conclusion from Experiments :

Rutherford's  nuclear model of Atom.

1.   Most part of the atom is empty space.(hollow)

2.  There are some positive charge inside atom in a very small space.

3. The positive charge inside atom is concentrated to extremely small space called nucleus.  (10^-15 m)

4. Number of alpha particles scattered at particular angle Ø is different  for different foil.           ● Different element have different +ve charge in their nucleus. 

5.  the electron  are attracted by +ve nucleus but electron don't move towards nucleus. it utilises the force as centripetal force and revolve it in Any circular orbit around the Nucleus.                     • electrostatic force = centripetal force

Drawback of Rutherford Model of Atom :

● he can't explain stability of Atom.

      (  Maxwell, An  Accelerated charge  particles  emits radiation.  electron have Acceleration  it is also charged particles  )

● He can't explain discrete Atomic spectrum.




This is Shoaib Alam, Man behind your ElectronGate

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