Module 1 : History of Atomic & Molecular Physics and basic backgrounds
Lecture 3 : Formulation of Old Quantum theory
The Rutherford Experiments
Rutherford discovered (alpha)-particles (nuclei of helium atoms with +2 charge))
In 1909, he with co-workers (Hans Geiger and Ernest Marsden) experimented with streams of alpha particles passing through a thin gold foil as shown in Figure - 3.3 a.
The foil thickness was
Concept of the Experiment:
Figure - 3.3 a
Experimental Result:
Figure - 3.3 b
Observations:
Almost all particles went through the gold foil with very slight deflections as shown in Figure - 3.3.
A very, few particles were reflected – scattered by more than of as shown in Figure - 3.3.
(alpha)-particles (nuclei of helium atoms with +2 charge)) 
particles went through the gold foil with very slight deflections as shown in Figure - 3.3.
particles were reflected – scattered by more than of 
as shown in Figure - 3.3.