Rutherford Model (English)

1-1: The Rutherford Model of the Nuclear Atom

We learned

Rutherford's atomic model

(or "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?"

).

[Rutherford Scattering]

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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