Q4 of 21 Page 102

What were the three major observations Rutherford made in the gold foil experiment?

Ernest Rutherford was interested in knowing how the electrons are arranged within an atom. Therefore he designed an experiment for this. In this experiment, fast moving alpha (α)-particles were made to fall on a thin gold foil.

Three major observations that he made are as follows:


1. Most of the fast moving α-particles passed straight through the gold foil. The figure below shows the same.



2. Some of the α-particles were deflected by the foil by small angles. The figure below shows the same.



3. Surprisingly one out of every 12,000 alpha particles appeared to rebound. The figure below shows the same.



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Sketch Rutherford's atomic model. Why Rutherford's model of the atom is called the planetary model?

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Put tick (√) against correct choice and cross (×) against wrong choice:

In Rutherford's gold foil experiment, majority of alpha particles passed directly through the gold foil. This observation leads to which conclusion?


a) The positive region of the atom is very small.


b) The majority of the atom must consist of empty space.


c) The alpha particle makes a direct hit on the positive region.


d) The positive region of the atom is very dense.