Period+4+Rutherford


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What was Rutherford's educational background? How was he introduced to the field of research dealing with the structure of the atom? Describe the experiment Rutherford used to study the structure of the atom. Rutherford went on to do additional research of importance. Describe this research.//**

Ernest Rutherford

Ernest Rutherford was born in 1871 and he died in 1937. Rutherford's family emigrated from England to New Zealand before he was even born. His family had run a farm where Ernest was born. Ernest Rutherford was very good in his school career. He won a university scholarship. After he went to college won yet another scholarship to study at Cambridge University in England. While Rutherford was there he met J.J. Thomson. Thomson encouraged Rutherford to study recently discovered x-rays. This influenced his career and led him to name some basic principles in physics. These were alpha, beta, and gamma rays. Also, he named and found the proton, neutron, half-life, and daughter atoms.

Ernest learned early on that all known radioactive elements emit two kinds of radiation: positively and negatively charged, or alpha and beta. Rutherford showed that every radioactive element decreases in radioactivity over a unique and regular time, or half-life, to make it stable.

In 1901 and 1902, he worked with Frederick Soddy to prove that atoms of one radioactive element would spontaneously turn into another, by expelling a piece of the atom at high velocity. A lot of scientists didn't like the idea of alchemy. They believed the atom is indivisible and unchangeable. In 1904 Rutherford's achievements were recognized. Over seven years he had published 80 papers.

In 1907, Ernest went to the University of Manchester. With Hans Geiger, they set up a center to study radiation. Rutherford wanted to change the face of physics. He discovered the atomic nucleus and developed a model of the atom that was similar to the solar system. Supposedly, like the planets, electrons orbited a central, sun-like nucleus. People started to accept this model after it was modified with the quantum theory by Niels Bohr. Rutherford received the Nobel Prize in Chemistry in 1908. Much of the basis of Rutherford's experiment involving the structure of atoms came from an experiment first completed by Geiger and Marsden. There are three different factors that show the actions of the nucleus in an atom. The first is that since a nucleus is so small, alpha particles would move straight through the gold foil used by Geiger and Marsden as if nothing was there. The second was that some alpha particles would pass near gold atom nuclei while going through the foil and would be deflected a degree or two off of their original path. The final factor is that an extremely small amount of alphas would smash into a nucleus almost head-on. Since alphas travel at 10% the speed of light, the alphas would penetrate the atom and almost enter the nucleus. However, it would quickly be repulsed back, sometimes turning the alpha ray around more than 90 degrees.

Ernest left his research to help the British Admiralty with problems of submarine detection during World War I, but he soon was back working in the lab. He managed to produce the disintegration of a non-radioactive atom, dislodging a single particle. The particle had a positive charge, so it must have come from nucleus: he called this new particle a proton. With this experiment, he was the first human to create a "nuclear reaction" even though it was weak.

In 1919, Rutherford took over as director of the Cavendish Laboratory. He was an outstanding mentor and researchers were attracted there by him scientific achievements. As years went on, he took more supervision and less research. In 1931, he was made the first Baron Rutherford of Nelson. This allowed him to join the House of Lords. Rutherford was anti-Nazi and served as president of the Academic Assistance Council. This was established to help German refugees. He would not help Fritz Haber who had been important in creating chemical weapons in World War 1. Ernest Rutherford died in 1937.

Much of the basis of Rutherford's experiment involving the structure of atoms came from an experiment first completed by Geiger and Marsden. There are three different factors that show the actions of the nucleus in an atom. The first is that since a nucleus is so small, alpha particles would move straight through the gold foil used by Geiger and Marsden as if nothing was there. The second was that some alpha particles would pass near gold atom nuclei while going through the foil and would be deflected a degree or two off of their original path. The final factor is that an extremely small amount of alphas would smash into a nucleus almost head-on. Since alphas travel at 10% the speed of light, the alphas would penetrate the atom and almost enter the nucleus. However, it would quickly be repulsed back, sometimes turning the alpha ray around more than 90 degrees.

REFERENCES http://nobelprize.org/nobel_prizes/chemistry/laureates/1908/rutherford-bio.html http://en.wikipedia.org/wiki/Ernest_Rutherford http://www.pbs.org/wgbh/aso/databank/entries/bpruth.html http://dbhs.wvusd.k12.ca.us/webdocs/AtomicStructure/Rutherford-Model.html