By Leo Massey and Chris Pak

Henri Becquerel  Did most of his work within France  Born December 15, 1852 in Paris, France- Died in Brittany, France on August 25, 1908  Discovered radioactivity in 1896 with Henri Poincaré in x-rays by accident in his laboratory

Pierre Curie  Born May, in Paris, France-Died April 19, 1906 in accident in Paris  Worked with brother, Jacques; found magnetic props. of sub. alter with diff. temps. (Curie point)  Isolated elements, radium and polonium with wife, Marie, who named polonium after her home Poland

Marie Curie  (Marie Slodowska) Born November 7, 1867 Warsaw, Poland-Died July 4, 1934  Found radioactive material; named it radium, found in mineral named pitchblende  Worked with husband, Pierre on finding new radioactive element polonium in 1898

Henri Becquerel and Radioactivity  Put potassium uranyl sulfate into sun, placed it on photographic plates wrapped in black paper, believed that it would absorb the sun energy and send rays  Hypothesis disproved, but Becquerel developed his photographic plates anyway  Images were strong & clear; showed that uranium emitted radiation without energy source like the sun and discovered radiation

Radioactivity Discovery Significant Because…  Contributions were significant to chemistry’s subfield, radioactivity because without foundation, never would have expanded the field  Never would have allowed the Curie’s to coin the phrase, “radioactivity” or for them make huge advancements in the radioactivity field  Ex. Them discovering radium and polonium

Becquerel and the Atomic Theory  Placed double sulfate of uranium and potassium on photographic plates and laid them in sun to absorb energy  Overcast, so no sunshine but took plates out of place and found that the images were clear, concluded that uranium cause radiation  This radiation made by chemicals spontaneously decomposing and giving off very penetrating rays, showed atoms could be split even further

Marie and Pierre Curie Finding Radium and Polonium  Were working with bismuth fractions and found that once more bismuth taken away, stronger residue left  June 1898 strong element from pitchblende was metal named polonium  December 26, 1898 found new element similar to pure barium, named it radium

Radium and Polonium Significant Because.  Element Radium used to cure certain diseases and cancer; still used to this day  Radium used in x-ray technology  Polonium used today as a heat source in space vehicles and as a alpha radiation

Curies and the Atomic Theory  Used Becquerel’s discovery, studied uranium and found that left overs of uranium ore is more radiant than itself  Then found that ore had elements of polonium and radium  Study of radioactivity helped develop atomic theory by showing that elements and atoms could be isolated and split apart

Sources      Biographies/Curie-Marie.html Biographies/Curie-Marie.html   Textbook- Chemistry Matter and Change page 806 