explain Rutherford's atomic model with experiment , observation and conclusion
Answers
Answer:
Introduction:
Rutherford proposed that an atom is composed of empty space mostly with electrons orbiting in a set, predictable paths around fixed, positively charged nucleus.
Working:
In Rutherford’s experiment, he bombarded high energy streams of α-particles on a thin gold foil of 100 nm thickness. The streams of α-particles were directed from a radioactive source. He conducted the experiment to study the deflection produced in the trajectory of α-particles after interaction with the thin sheet of gold. To study the deflection, he placed a screen made up of zinc sulfide around the gold foil. The observations made by Rutherford contradicted the plum pudding model given by J.J. Thomson.
Observations :
On the basis of the observations made during the experiment, Rutherford concluded that
1)Major space in an atom is empty – A large fraction of α-particles passed through the gold sheet without getting deflected. Therefore, the major part of an atom must be empty.
2)The positive charge in an atom is not distributed uniformly and it is concentrated in a very small volume – Few α-particles when bombarded were deflected by the gold sheet. They were deflected minutely and at very small angles. Therefore he made the above conclusion.
3)Very few α-particles had deflected at large angles or deflected back. Moreover, very few particles had deflected at 180o. Therefore, he concluded that the positively charged particles covered a small volume of an atom in comparison to the total volume of an atom.
Postulates :
1)An atom is composed of positively charged particles. Majority of the mass of an atom was concentrated in a very small region. This region of the atom was called as the nucleus of an atom. It was found out later that the very small and dense nucleus of an atom is composed of neutrons and protons.
2)Atoms nucleus is surrounded by negatively charged particles called electrons. The electrons revolve around the nucleus in a fixed circular path at very high speed. These fixed circular paths were termed as “orbits.”
3)An atom has no net charge or they are electrically neutral because electrons are negatively charged and the densely concentrated nucleus is positively charged. A strong electrostatic force of attractions holds together the nucleus and electrons.
4)The size of the nucleus of an atom is very small in comparison to the total size of an atom.
Conclusion:
Even though the early atomic models were inaccurate and could not explain the structure of atom and experimental results properly. But it formed the basis of the quantum mechanics and helped the future development of quantum mechanics.
Answer:
Rutherford Atomic Model
According to Rutherford, an atom is primarily made up of empty space, with the electrons orbiting the positively charged nucleus in a regular, predictable pattern.
- In Rutherford's experiment, he bombarded a 100 nm-thick gold foil with high-energy streams of α -particles.
- The radioactive source was used to direct the streams of α -particles.
- He carried out the experiment to investigate how the thin sheet of gold affected the trajectory of the α-particles.
- He surrounded the gold foil with a zinc sulfide screen to observe the deflection.
- Rutherford's observations ran counter to J.J. Thomson's model of plum pudding.
Observations of Rutherford Model Experiment
Rutherford determined based on his findings during the experiment that
- A substantial percentage of α-particles travelled through the gold sheet without being deflected, indicating that the majority of space in an atom is unoccupied. As a result, the majority of an atom must be empty.
- When bombarded, few α-particles experienced extremely slight angles of deflection because the positive charge in an atom is not spread uniformly and is concentrated in a very limited volume.
- Only a small number of α-particles have returned or deflected at large angles. Furthermore, just a few particles had deflected at 180°. As a result, he came to the conclusion that the positively charged particles only occupied a small portion of an atom's overall volume.
Rutherford's atomic model postulates based on findings and observations
- An atom is made up of positively charged particles. A large portion of an atom's mass was concentrated in a very small area. This portion of the atom was referred to as the nucleus of an atom. Later it was discovered that neutrons and protons make up the incredibly small and dense nucleus of an atom.
- The electrons that surround an atom's nucleus are negatively charged particles. The electrons travel at a very high speed in a fixed circular path around the nucleus. We called these fixed circular pathways "orbits."
- Because electrons are negatively charged and the tightly concentrated nucleus is positively charged, atoms have no net charge or are electrically neutral. The nucleus and electrons are held together by a strong electrostatic force of attraction.
- When compared to the overall size of an atom, the nucleus' size is extremely small.
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