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|1-1: The Rutherford Model of the Nuclear Atom|
Rutherford's atomic model
"the Rutherford Model of the Nuclear Atom")
on a previous page
of the present seminar,
"Microscopic World - 1 -
(Mysteries in the Atomic World)",
and we could know
the internal structure of an atom.
Now we know that there exists
a heavy nucleus at the center
of the atom
being surrounded by light electrons
whose number is Z
that is just equal to
the atomic number.
(See the figure below.)
From the success of this Rutherford's atomic model, people realized the existence of the atomic nucleus for the first time in the history. (See the page "What is the Atomic Nucleus?" ).
E. Rutherford (UK, 1871-1937) investigated whether the experimental results of the alpha particle scattering could be explained well by the Rutherford atomic model. He derived the famous Rutherford scattering formula standing on the viewpoint of the Rutherford model and he found that the results of this formula fit well to the experimental data (1911).
Rutherford assumed that the total positive charge in an atom, +Ze, concentrates on the central point of the atom, i.e., the nucleus, and the incident alpha particle is scattered with a repulsive Coulomb force exerted by this nuclear point charge. The results of his analysis were very much successful; they fit very well to the experimental data of the alpha-particle scattering.
From this Rutherford's analysis, it was made clear that the almost total mass of the atom is carried by the nucleus. On the other hand, the size of the nucleus is extremely small compared with the whole size of the atom; it is smaller than 1/10000 of size of the whole atom.
[The Rutherford Model
of the Nuclear Atom]
This is a schematic image of the Rutherford atomic model. The size of the nucleus is extremely small compared with the whole atom.
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