Starting with several tons of pitchblende, the Curies isolated two new radioactive elements after months of work: polonium, which was named for Marie’s native Poland, and radium, which was named for its intense radioactivity.
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He conducted his famous oil drop experiment in 1913 while working at the University of Chicago. Millikan was able to observe the motion of the oil drops with a microscope and found that the drops lined up in a specific way between the plates, based on the number of electric charges they had acquired. Thomson contributed extensively to the field of chemistry by discovering the existence of electrons, developing the mass spectrometer and determining the presence. Robert Millikan was born in Morrison, Illinois in 1868. The oil drops picked up static charge and were suspended between two charged plates.
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Although a mathematician and an experimental physicist by training, J. She found that one particular uranium ore, pitchblende, was substantially more radioactive than most, which suggested that it contained one or more highly radioactive impurities. Joseph John Thomson’s contributions to science helped revolutionize the understanding of atomic structure. Marie Curie coined the term radioactivity (from the Latin radius, meaning “ray”) to describe the emission of energy rays by matter. Becquerel’s work was greatly extended by Marie Curie (1867–1934) and her husband, Pierre (1854–1906) all three shared the Nobel Prize in Physics in 1903. The second line of investigation began in 1896, when the French physicist Henri Becquerel (1852–1908) discovered that certain minerals, such as uranium salts, emitted a new form of energy. With this information and Thomson’s mass-to-charge ratio, Millikan determined the mass of an electron: Using the smallest charge obtained and Thomsons charge/mass ratio the electron mass is roughly 1/2000 the mass of the lightest atom. In 1909 Robert Millikan used the classic oil drop experiment to determine the charge on these particles. Subsequently, the American scientist Robert Millikan (1868–1953) carried out a series of experiments using electrically charged oil droplets, which allowed him to calculate the charge on a single electron. Atomic Theory Daltons Atomic Theory Early Atomic Theory.
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Another set of electrode plates deflect the ray, with the ray bending towards the positive plate. He charged droplets of oil between two electrodes and balanced the gravitational force with the upward forces, using mechanical equilibrium to determine the charge, which he found within one. Schematic of cathode ray tube with deflection. Robert Millikan was a physicist who discovered the elementary charge of an electron using the oil-drop experiment. Image used with Permission (CC BY-SA-NC). As the cathode rays travel toward the right, they are deflected toward the positive electrode (+), demonstrating that they are negatively charged. \): Deflection of Cathode Rays by an Electric Field.