Joseph John Thomson Essays - Electron Beam, Charge Carriers

Joseph John Thomson Essays - Electron Beam, Charge Carriers Joseph John Thomson Biography Joseph John Thomson was born in 1856 in Cheetham Hill, Manchester, England. His mother, Emma Swindells, came from a local textile family. His father, Joseph James Thomson, ran an antiquarian bookshop founded by a great-grandfather. He had a brother two years younger than him, Frederick Vernon Thomson. His early education was in small private schools where he demonstrated great talent and interest in science. In 1870 he was admitted to Owens College at the unusually young age of 14. His parents planned to enroll him as an apprentice engineer to Sharp-Stewart & Co, a locomotive manufacturer, but these plans were cut short when his father died in 1873. He moved on to Trinity College, Cambridge in 1876. In 1880, he obtained his BA in mathematics (Second Wrangler and 2nd Smith's Prize) and MA (with Adams Prize) in 1883. In 1884 he became Cavendish Professor of Physics. One of his students was Ernest Rutherford, who later succeeded him in the post. In 1890 he married Rose Elisabeth Paget, daughter of Sir George Edward Paget, KCB, a physician and then Regius Professor of Physic at Cambridge. They had one son, George Paget Thomson, and one daughter, Joan Paget Thomson. One of Thomson's greatest contributions to modern science was in his role as a highly gifted teacher: seven of his research assistants and his son won Nobel Prizes in physics. His son won the Nobel Prize in 1937 for proving the wavelike properties of electrons. He was awarded a Nobel Prize in 1906, "in recognition of the great merits of his theoretical and experimental investigations on the conduction of electricity by gases." He was knighted in 1908 and appointed to the Order of Merit in 1912. In 1914 he gave the Romanes Lecture in Oxford on "The atomic theory". In 1918 he became Master of Trinity College, Cambridge, where he remained until his death. He died on 30 August 1940 and was buried in Westminster Abbey, close to Sir Isaac Newton. Thomson was elected a Fellow of the Royal Society on 12 June 1884 and was President of the Royal Society from 1915 to 1920. (1) J.J. Thomson's Atomic Model and Theory Thomson discovered the electron in the year 1897. His work put forward a new theory, that atom was made up of small particles.Thus he discovered the electrons. He proved his theory using the cathode ray tube. Scientists had already done many experiments to find the structure of the atom. They passed an electric current through a vacuum tube. They saw a light glowing inside the tube. It travelled in a straight line. They could not explain the phenomenon. Thomson did more experiments on the cathode tube. He placed two electric plates on its path. One was positively charged. The other was negatively charged. The glowing light bent towards the positively charged plate.and found that the glowing materials bent towards the positively charged plate. He found out that the glowing light were smaller particles. They were smaller than the atom. Thus Thomson found the particle called electron. Thus J.J.Thomson's atomic theory was found. Thomson suggested that the electrons came out ofthe trace gas that was inside the cathode tube. Thus a new theory that atoms were made of tiny particles surfaced. Thomson discovered the electrons and it was proved that atoms were made up of protons, electrons and neutrons. Thus Thomson proved that the atom was divisible. Since the atom was neutral, Thomson suggested that the negatively charged electron equalled the positively charged proton and neutrons had no charges.Thomson suggested to consider the atom as a sphere. It has positively charged particles. The positively charged particles is surrounded by the negatively charged electons. The electrons were placed there due to electrostatic forces. (2) What is a Cathode Ray Tube? Even without consciously realizing it, most of us are already aware of what a cathode ray tube is. Look at any glowing neon sign or any old-fashioned television set, and you are looking at the modern descendants of the cathode ray tube. Physicists in the 19th century found out that if they constructed a glass tube with wires inserted in both ends, and pumped out as much of the air as they could, an electric charge passed across the tube from the wires would