In Geiger-Marsden experiment, at the point of closest approacha)the ki...
The kinetic energy is zero and the electrical potential equals the initial kinetic energy supplied
In Geiger-Marsden experiment, at the point of closest approacha)the ki...
At the point of closest approach in the Geiger-Marsden experiment, the following conditions hold true:
Explanation:
The Geiger-Marsden experiment, also known as the gold foil experiment, was conducted in 1909 by Hans Geiger and Ernest Marsden under the supervision of Ernest Rutherford. The experiment aimed to understand the structure of the atom and verify the plum pudding model proposed by J.J. Thomson.
Objective of the experiment:
The objective of the Geiger-Marsden experiment was to study the scattering of alpha particles (helium nuclei) by a thin gold foil. By observing the scattering pattern, the researchers aimed to gain insights into the structure of the atom and determine the distribution of positive charge within it.
Experimental setup:
The experimental setup consisted of a radioactive source emitting alpha particles, a lead block to shield against other radiation, and a gold foil placed in the path of the alpha particles. Behind the gold foil, a fluorescent screen was placed to detect the scattered alpha particles.
Observations:
During the experiment, most of the alpha particles passed through the gold foil with minimal deflection, suggesting that the atom is mostly empty space. However, a small fraction of the alpha particles experienced significant deflection, indicating the presence of a concentrated positive charge within the atom.
Closest approach:
At the point of closest approach, the alpha particle is closest to the nucleus of the gold atom. This occurs when the repulsive electrical force between the positive charge of the alpha particle and the positive charge of the gold nucleus is at its maximum.
Kinetic energy and electrical potential:
At the point of closest approach, the kinetic energy of the alpha particle is zero. This is because as the alpha particle moves towards the nucleus, its kinetic energy is gradually converted into potential energy due to the increasing repulsive force.
The electrical potential at the point of closest approach is equal to the initial kinetic energy supplied to the alpha particle. This is because the electrical potential energy between two charged objects is equal to the work done in bringing them together from infinity.
Therefore, the correct option is 'C': the kinetic energy is zero and the electrical potential equals the initial kinetic energy supplied.