This is the presentation of Rutherford model of an atom.

3. I would like to thank my science teacher
Shalini Mam and my parents for helping me
in making this presentation. My parents
helped me in editing of this presentation.
They also helped me in formatting the
matter of the presentation. I collected
the information from the internet and
from some books.My other gratitude I
would like to convey to my school who
suggest me to make this and to have
marks for adding it into examination.

4. Ernest Rutherford (1871-1937)
Ernest Rutherford, first known as Baron
Rutherford (30 August 1871-19 October
1937) was a New Zealand-born British
chemist and physicist who became
known as the father of nuclear
physics. He is considered the greatest
experimentalist since Michael
Faraday (1791–1867). In early work he
discovered the concept of
radioactive half-life, proved that
radioactivity involved the
transmutation of one chemical element
to another, and also differentiated and
named alpha and beta radiation.

5. This work was done
at McGill
university in Canada.
It is the basis for
the Nobel Prize in
Chemistry he was
awarded in 1908 "for
his investigations
into the
disintegration of the
elements, and the
chemistry of
radioactive
substances ”.
Structure of an Atom

6. Rutherfordscattering experimentis a phenomenon in physics that was explained
by ErnestRutherfordin 1911, which led to the development of the Rutherford
model (planetary model) of the atom, and eventually to the Bohr Model. It is now
exploited by the materials analytical technique Rutherford Backscattering. Rutherford
scattering is also sometimes referred to as Coulomb scattering because it relies only
upon static electric (Coulomb) forces, and the minimal distance between particles is set
only by this potential. The classical Rutherford scattering of alpha particles against gold
nuclei is an example of "elastic scattering" because the energy and velocity of the
outgoing scattered particle is the same as that with which it began.

7. Rutherford also later analyzed inelastic scattering when he
projected alpha particles against hydrogen nuclei
(protons) ; however this latter process is not referred to as
"Rutherford scattering", although Rutherford was first to
observe it. At the end of such processes, non-coulombic
forces come into play. These forces, and also energy gained
from the scattering particle by the lighter target, change the
scattering results in fundamental ways which suggest
structural information about the target. A similar process
probed the insides of nuclei in the 1960s, and is called deep
inelastic scattering.

8. ¡Gold Foil
¡Lead Block
Shield
¡Zinc Sulphide
Screen
¡Source of
Alpha particles

9. A narrow beam of alpha particles was
aimed at a thin sheet of gold foil.
A zinc sulfide coated screen surrounding the
gold foil produced a flash of light when struck
by an alpha particle (radioactive materials
expose photographic film).
By noting where the flashes occurred, the
scientists could determine if the atoms in the
gold foil deflected the alpha particles.

10. § Most of the particles went
straight through the gold foil
§ Several particles were
deflected straight back
toward the source!
§ A few particles were
deflected at large angles.

11. INTERPRETING THE OBSERVED
DEFLECTIONS
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gold foil
Deflected particle
Undeflected
particles
*
*
Beam of
alpha
particles
*

12. As a result of his
observations, Rutherford
suggested that the atom had
a positively charged centre
which contained most of the
mass.
he called the heavy
positively charged centre
the nucleus.
he went on to suggest that
the nucleus was surrounded
by orbiting electrons
required for electrical

13. The major drawback of Rutherford’s
model of an atom is that it does not explain
the stability of the atom.
In the Rutherford’s model of an atom, the
negatively charged electrons are revolving around
the positively charged nucleus in circular paths.
Now, we know that if an object moves in a circular
path, then its motion is said to be accelerated. This
means that the motion of an electron revolving
around the nucleus is accelerated.

14. If we apply this electromagnetic
theory to the Rutherford’s model of
an atom, it will mean that the
negatively charged electrons
revolving around the nucleus with
accelerated motion , will lose their
energy continuously by radiation.
Thus, the energy of revolving
electrons will decrease gradually
According to the electromagnetic theory of
physics, if a charged particle undergoes
accelerated motion, then it must radiate energy
(or lose energy) continuously.
and their speed will also go on decreasing. The electrons will
then be attracted more strongly by the oppositely charged
nucleus due to which they will come more and more close to
the nucleus. And ultimately the electrons should fall into the
nucleus by taking a spiral path. This should make the atom
very unstable and hence the atom should collapse.