Gold foil experiment

[[Image:Rutherford gold foil experiment results.png|right|200px|thumb|Top: Expected results: alpha particles passing through the plum pudding model of the atom undisturbed.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Bottom: Observed results: a small portion of the particles were deflected, indicating a small, concentrated positive charge.]]

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

The Gold foil experiment, or Geiger-Marsden experiment was an experiment done by Hans Geiger and Ernest Marsden in 1909, under the direction of Ernest Rutherford at the Physical Laboratories of the University of Manchester which led to the downfall of the plum pudding model of the atom.

Related Topics:
Hans Geiger - Ernest Marsden - 1909 - Ernest Rutherford - University of Manchester - Plum pudding model

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

They measured the deflection of alpha particles directed normally onto a sheet of very thin gold foil. Under the prevailing plum pudding model, the alpha particles should all have been deflected by at most of a few degrees. However they observed that a very small percentage of particles were deflected through angles much larger than 90 degrees. From this Rutherford concluded that the atom contained a very small positive charge which could repel the alpha particles if they came close enough, subsequently developed into the Bohr model.

Related Topics:
Alpha particle - Bohr model

~ ~ ~ ~ ~ ~ ~ ~ ~ ~