Rutherford, Ernest radioactivity studied

Not long after radioactivity was discovered by Becquerel, scientists began investigating its nature. In 1899, Ernest Rutherford, who had studied... 

Rutherford, Ernest (1st Baron Rutherford of Nelson) (1871-1937) New Zealand-born British pioneer of subatomic particle physics who proposed the nuclear structure of the atom. He studied the radioactive disintegration of elements and correctly predicted the existence of the neutron. Rutherford won the Nobel Prize in chemistry in 1908. 

Working in his laboratory at Montreal s McGill University, Ernest Rutherford studied the chemistry of radioactive elements intensively from 1898 to 1907. His efforts would lead to a Nobel Prize in Chemistry in 1908. Greater achievements lay ahead, however. 

Sir Ernest Rutherford was born in 1871 in Nelson, New Zealand. After studying at New Zealand University and Cambridge, he went to Canada in 1898 as a professor of physics at McGill University. After serving there for nine years and carrying out many remarkable researches in radioactivity, he became professor of physics at Manchester University, and in the following year he was awarded the Nobel Prize in chemistry. In 1919 he became a professor at Cambridge (72). 

The last sites visited in this chapter are associated with Ernest Rutherford and Frederick Soddy, pioneers in the study of radioactivity. Radioactivity is one of the phenomena that led chemists and physicists to understand that atoms were not indestructible or indivisible. 

Scientists have known since 1896 that many nuclides are radioactive—that is, they spontaneously emit radiation. Early studies of radioactive nuclei, or radionuclides, by the New Zealand physicist Ernest Rutherford in 1897 showed that there are three common types of radiation with markedly different properties alpha (a), beta (f3), and gamma (y) radiation, named after the first three letters of the Greek alphabet. 

Moseley s work was based on X-ray diffraction studies that revealed an even more powerful proof of the unity of the elements than Mendeleev s table of chemical characteristics. Moseley had worked with Ernest Rutherford (1871-1937) on radioactivity, but in 1912 he decided to use X-ray diffraction to examine the characteristics of the elements. He received training from Lawrence Bragg (1890-1971), the world s leading X-ray diffraction expert, and in 1913 began charting the X-ray spectra of the metallic elements. 

Medieval alchemists spent years trying to convert other metals into gold without success. Years of failure and the acceptance of Dalton s atomic theory early in the nineteenth century convinced scientists that one element could not be converted into another. Then, in 1896 Henri Becquerel discovered radioactive rays (natural radioactivity) coming from a uranium compound. Ernest Rutherford s study of these rays showed that atoms of one element may indeed be converted into atoms of other elements by spontaneous nuclear disintegrations. Many years later it was shown that nuclear reactions initiated by bombardment of nuclei with accelerated subatomic particles or other nuclei can also transform one element into another—accompanied by the release of radiation (induced radioactivity). 

Ernest Rutherford (Baron Rutherford), born near Nelson New Zealand, 1871. Studied at Cambridge under J. J. Thomson. Professor McGill University (Montreal), Manchester, and Cambridge. Nobel prize in chemistry 1908 for work on radioactivity, alpha particles, and atomic stracture. Knighted 1914. Died London, 1937. 

In 1911, Ernest Rutherford (1871-1937) began to study how positively charged alpha particles (radioactive particles you will read more about later in this chapter) interacted with solid matter. With a small group of scientists, Rutherford conducted an experiment to see if alpha particles would be deflected as they passed through a thin gold foil. 

Further study of radioactivity, principally by the British scientist Ernest Rutherford ( FIGURE 2.7), revealed three types of radiation alpha (a), beta (j8), and gamma (y). The paths of a and j8 radiation are bent by an electric field, although in opposite directions y radiation is unaffected by the field (T FIGURE 2.8). 

Marie and Pierre Curie examined the radiation emitted by radium. They found that all substances near the radiation source became radioactive themselves. The activity even remained some time after the removal of the emitting radium. It was questioned whether there is some radioactive force that was transferred with the radiation and was induced in the receiving substance. In 1900 F. Dom in Halle, Germany, reported on a study of an isotope emanating from radium and, because of that, certainly incorrectly, was credited with the discovery of radon. In fact Ernest Rutherford (1871-1937) and Frederick Soddy (1877-1956) were the first to isolate radon and also the first to really understand the nature of radon. In the first decade of 1900 they worked at McGill University in Montreal, Canada, and carried out very comprehensive work on radioactivity [52.10]. They discovered that the emanation from radium was a gas of the same type as the noble gases. Ramsay at University College in London completed the spectral work. He showed that the spectrum of radon resembled that of xenon. He also showed that the formation of radon was accompanied by the simultaneous production of helium, as he also observed its spectrum. This observa-... 

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