Rutherford Atomic Theory

During the race in finding out the right model that could represent the atomic structure, many scientists came and the second amongst them was a physicist from New-Zealand named Ernest Rutherford.

Rutherford again did his studies with respect to the Thomson model and for that he couldn’t agree much, so he decided to do his own experiments and research to give out the results for how the atomic structure basically exists in nature.

Geiger-Marsden Experiment   

Aim: To investigate the structure of atom

Requirements: A microscope, a thin piece of gold foil, 360 degree phosphorescent screen of zinc sulphide, and radioactive Alpha source.

Procedure: 

1. Place the thin sheet of gold foil in between the 360 degrees.
2. Phosphorescent zinc sulphide screen and the Alpha source.
3. Point the Alpha particles being created by the radioactive element, at the piece of gold foil.
4. Let the Alpha particles be emitted by the Alpha source as probes to hit the 100nm thick gold foil.
5. Observe with the help often microscope the different parts of the screen and look for little flashes of light.
6. Note down the different angles at which the beam of Alpha particles reflect.

Observation:

You might notice three different types of observations:-

• First of all you will see some of the Alpha particles that surpass the 100nm thick gold sheet as it is and hit the phosphorescent screen.
• This kind of Alpha particles will be in large amounts.
• The second observation will be that some of the Alpha particles reflect from the gold sheet forming acute angles.
• This will be fewer in amount.
• The last but not the least observation will be that few Alpha particles will hit the gold foil and reflect back forming an obtuse angle, and some of them will form about 180 degree as well. 

Result:

• From the above monitoring it was concluded that the particles that went across the foil remarked that the Atom was mostly empty.
• But the particles that deflected in small amount which is making an acute angle designated that, they were positive charges in the atom which were not uniformly distributed and same did large reflection point at, that the positive charges were present inside the atom but in a very small amount( in a condensed manner).
• By this he pointed that high Central charge was present into a very minute volume in comparison to the rest of the atom and through this he gave the knowledge about the nucleus, pointing it as a central charge which is tiny in size and heavy.

Structure of Atomic Model proposed by Rutherford

The cation particles and most of the mass of an atom were focused in an extraordinarily minute volume. He referred to this location of the atom as a sort of central charge in a big way.

The Rutherford model proposed that the negatively charged species definitely surround the kind of central charge of an atom, which for the most part is fairly significant. He also claimed that the electrons surrounding the nucleus revolve around it.

Electrons  being negatively charged and the centre of the atom being a mass of positive charge, are held together by using a sturdy electrostatic force of attraction, which for the most part is quite important in order to explain how electrons and the central charge acquire a sustainable balance.

Limitations     

1. Rutherford’s proposal of orbits in which the  negatively charged electrons revolve around the central charge, was not found to be in accordance with the theory of Maxwell. 
2. Also couldn’t define the positioning of electrons in the atom.

Conclusion      

A physicist from New-Zealand named Rutherford again experimented on the atomic structure when he was not able to make accordance with Thomson Atomic Model, gave his own Model was proved to be the base for research on the structure of model but it faced some limitations that were late overcome by different scientists like the stability and positioning of electrons in the respective atom.