PRESENTATION OUTLINE
BACKGROUND
- He was born August 1871.
- In early work he discovered the concept of radioactive.
- He was born in New-Zealand.
- He was the one that followed scientist , Michael Faraday.
DATES
- In 1898, Rutherford was appointed to the vacant chair of physics at McGill University in Montreal, Canada.
- In 1907, Rutherford was appointed professor of physics at the University of Manchester, England.
- In 1900, he married Mary Georgina Newton, and they had a daughter, Eileen Mary, the next year.
- 1911 exposed his results
- 1920 rutherford proposed the name proton for the positively charged particles in the nucleus of an atom
Experimental design
Rutherford started to study the effect of x-rays on various materials. After discovering radioactivity. Then he turned to the study of the particles emitted by uranium metal and it's compounds.
Procedures of the experiment
Rutherford had to develop a way of counting individual particles, he found that a screen coated with zinc sulfide admitted a flash of light each time it was hit by a particle. Then him and his partner Hans Geiger would try to count the flashes of light given by the screen.
Rutherford found that a narrow beam of particles was broadened when it passed through a thin film of mica or metal, therefore they measured the particles with a thin piece of meta foil. When this foil was bombarded with particles, Geiger found that the scattering was small, on the order of degree.
Data collected
The results were consistent with rutherford's expectations. He knew that the particle had a considerable mass and moved quite rapidly.he therefore anticipated that all of the particles would be able to penetrate the mata foil, although they would be scattered slightly by collisions with the atoms through which the passed, in other words he expected the the particles to pass through the mata foil in the way a rifle bullet penetrate a bag of sand.
According to his calculations, the radius of the nucleus is at least 10,000 times smaller than the radius of an atom.
Conclusion
Rutherford concluded that there was only a way to express the results. He assumed that the positive charge and the mass of an atom are concentrated in a small fraction of the total volume of the atom, and then derived math equations for the scattering that would occur. The equations predicted that the number of particles scattered though a give angle should be proportional to the thickness of the foil and the square of charge on the nucleus, and also to the velocity with which the particles moved raised to the fourth power.
