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Radioactivity. The Discovery By:Kaitlin Shorr and Tara Monaghan . Henri Becquerel: Biography. Full Birth Name: Antoine Henri Becquerel Born: December 15, 1852, in Paris, France Died: August 25, 1908 Field: Nuclear Science Physics Occupation: physicist - PowerPoint PPT Presentation
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RadioactivityThe DiscoveryBy:Kaitlin Shorr and Tara Monaghan
Henri Becquerel: Biography
● Full Birth Name: Antoine Henri Becquerel
● Born: December 15, 1852, in Paris, France
● Died: August 25, 1908 ● Field: Nuclear Science Physics● Occupation: physicist● Education: École Polytechnique,
École des Ponts et Chaussées● 1897- researched the newly
discovered x-rays which led him to the phenomenon of radioactivity.
Henri Becquerel’s Scientific Work● Becquerel's earliest work:
was with the concern of plane polarization of light, with the phenomenon of phosphorescence and with the absorption of light by crystals (his doctorate thesis).
● He also worked on the subject of terrestrial magnetism.
● In 1896, his previous work overshadowed his discovery of the phenomenon of natural radioactivity.
Henri Becquerel's Discovery
● 1896: he used naturally fluorescent minerals to study the properties of x-rays.
● He exposed potassium uranyl sulfate to sunlight and then placed it on photographic plates wrapped in black paper.
● He believed that the uranium absorbed the sun’s energy and then emitted it as x-rays.
● A couple days went by and he tested it again by putting the uranium in a closed door with the photographic plate.
● It left a clear strong image on the photographic plate.
● When his experiment was disproved( 26th and 27th of February) he tested anyway and it proved that uranium emitted radiation with the source of the sun.
● He had, after his findings, discovered that uranium could produce a picture on the photographic plate without light, radioactivity.
Becquerel Apparatus ● used an apparatus to show that the radiation he discovered
could not be x-rays. ● x-rays are neutral and cannot be bent in a magnetic field. ● new radiation was bent by the magnetic field so that the
radiation must be charged and different than x-rays. ● when different radioactive substances were put in the magnetic
field, they deflected in different directions or not at all.● showed that there were three classes of radioactivity: negative,
positive, and electrically neutral.
Pierre Curie: Biography● Born: On May 15, 1859, in Paris,
France● Died: April 19, 1906● Education: Faculty of Sciences at
Sorbonne and got his doctorate the year he married Marie.
● Before he and his brother, Jacques, distinguished themselves in the study of the properties of crystals.
● In 1882, Pierre had headed the laboratory at the Ecole de Physique et de Chimie Industrielle in Paris.
Pierre Curie’s Scientific Work● studied the properties of
crystals○ discovered piezoelectricity
● studied the magnetic properties of materials
● constructed a torsion balance with a tolerance of 0.01 mg
● discovered Weiss-Curie’s Law
● discovered Curie temperature
Marie Curie: Biography● Born: As Maria Sklodowska in Warsaw, Poland on November 7,
1867● Died: July 4, 1934● Education: spent many years as a teacher and governess; joined
her sister, Bronia, in Paris to study mathematics and physics at Sorbonne
● earned degrees in both mathematics and physics in 1893 and 94● met physicist, Pierre Curie, and got married (1895)● had two children, Irene (1897) and Eve (1904).
Marie Curies’s Discovery● Marie
○ decided to study the mysterious radiation Becquerel had discovered
○ measured the strength of the radiation emitted from uranium compounds and found it proportional to the uranium content, constant over a long period of time, and uninfluenced by external conditions
● detected a similar immutable radiation in the compounds of thorium
● made the unexpected discovery that uranium pitchblende and the mineral chalcolite emitted about four times as much radiation as could be expected from their uranium content
● concluded that pitchblende contains a small amount of an unknown radiating element
• Used an electrometer to search for new substances which uses the level of radioactivity to determine the strength of the current
• discovered two new spontaneously radiating elements, which they name polonium and radium.
• colleague, Andre Debierne, discovered actinium
• began the task of isolating these elements so that their chemical properties could be determined.
Pierre Joins Marie in her work
Awards Won● the Curies and Becquerel
○ Nobel Prize in Physics for the discovery of radioactivity
● Marie Curie ○ Nobel Prize in chemistry for isolating radium
● "Pierre Curie - Biographical." Pierre Curie - Biographical. N.p., n.d. Web. 04 Nov. 2013. <http://www.nobelprize.org/nobel_prizes/physics/laureates/1903/pierre-curie-bio.html>.
● "Henri Becquerel - Facts." Henri Becquerel - Facts. N.p., n.d. Web. 04 Nov. 2013. <http://www.nobelprize.org/nobel_prizes/physics/laureates/1903/becquerel-facts.html>.
● "Pierre and Marie Curie." Pierre and Marie Curie. N.p., n.d. Web. 04 Nov. 2013. <http://chemistry.mtu.edu/~pcharles/SCIHISTORY/Marie_Curie.html>.
● "Marie Curie and the History of Radioactivity." - Online Science. N.p., n.d. Web. 06 Nov. 2013. <http://www.sciencemuseum.org.uk/onlinestuff/stories/marie_curie_and_the_history_of_radioactivity.aspx?page=2>.