Rutherford's Experiment

Rutherford Gold Foil Experiment:

Rutherford Gold Foil Experiment

Ruther Ford Alpha Scattering Experiment :

Ruther Ford Alpha Scattering Experiment

Made By Students of IX D:

Made By Students of IX D Aman Garg Satyajay Jethwa Priya Choudharry Rohan Jayaprakash Anirudh Verma

History:

History In Ernest Rutherford's laboratory, Hans Geiger and Ernest Marsden (a 20 yr old undergraduate student) carried out experiments to study the scattering of alpha particles by thin metal foils. In 1909 they observed that alpha particles from radioactive decays occasionally scatter at angles greater than 90°, which is physically impossible unless they are This led Rutherford to deduce that the positive charge in an atom is concentrated into a small compact nucleus. During the period 1911-1913 in a table-top apparatus, they bombarded the foils with high energy alpha particles and observed the number of scattered alpha particles as a function of angle. Based on the Thomson Model of the atom, all of the alpha particles should have been found within a small fraction of a degree from the beam, but found a few scattered alphas at angles over 140 degrees from the beam. Rutherford's remark "It was quite the most incredible event that ever happened to me in my life. It was almost as incredible as if you had fired a 15-inch shell at a piece of tissue paper and it came back and hit you." The scattering data was onsistent with a small positive nucleus which repelled the incoming positively charged alpha particles

Model of Experiment:

Model of Experiment

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In the early days of atomic theory, many physicists tried to explain the model of an atom. In 1902, Ernest Rutherford showed that alpha particles emitted from the decay of unstable radioactive materials were electrically charged helium nuclei travelling at high speed. In 1909, Rutherford used alpha particles to investigate the composition of gold foil (i.e. to explain the model of an atom). IN THE BEGINNING……

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To investigate the composition of gold foil using alpha particles (i.e. to explain the model of an atom). Aim

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Apparatus Rutherford’s alpha scattering apparatus: q a -source vacuum gold foil zinc sulphide detector

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Procedure Rutherford fired alpha particles through a piece of gold foil and used a zinc sulphide detector to detect the scattered alpha particles and their location. Formula for experiment are:

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Rutherford’s experiment found that: Most of the alpha particles passed through the gold foil undeviated. A few alpha particles were deflected from their path but continued through the gold foil. A small number of alpha particles rebounded. Results

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Modern measurements show that the average nucleus has a radius in the order of 10 -15 m. This is 100, 000 times smaller than the radius of a typical atom. Observations We observe that three rays are emitted from radioactive elements. They are alpha, beta and gamma in which alpha is positive ray beta is negative ray and gamma is neutral.

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As most alpha particles passed through the gold foil atoms undeviated, Rutherford concluded that most of the atom was actually empty space. From the results of his experiment, Rutherford explained: The deviation of some alpha particles from their original path were due to positive charges within the foil. Conclusion

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From the results of his experiment, Rutherford explained: Conclusion A small number of alpha particles had rebounded because they collided with something much larger and heavier and which contains a concentrated region of positive charge.

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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 neutrality. Conclusion

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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 neutrality. Conclusion

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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 neutrality. Conclusion

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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 neutrality. Conclusion

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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 neutrality. Conclusion

Shortfalls of Rutherford’s Model:

Shortfalls of Rutherford’s Model Did not explain where the atom’s negatively charged electrons are located in the space surrounding its positively charged nucleus. We know oppositely charged particles attract each other What prevents the negative electrons from being drawn into the positive nucleus? 41

Thank You :

Thank You