Returning to the field he had created, Becquerel made three more important contributions. One was to measure, in 1899 and 1900, the deflection of beta particles, which are a constituent of the radiation in both electric and magnetic fields. From the charge to mass value thus obtained, he showed that the beta particle was the same as Joseph John Thomson's recently identified electron. Another discovery was the circumstance that the allegedly active substance in uranium, uranium X, lost its radiating ability in time, while the uranium, though inactive when freshly prepared, eventually regained its lost radioactivity. When Ernest Rutherford and Frederick Soddy found similar decay and regeneration in thorium X and thorium, they were led to the transformation theory of radioactivity, which explained the phenomenon as a subatomic chemical change in which one element spontaneously transmutes into another. Becquerel's last major achievement concerned the physiological effect of the radiation. Others may have noticed this before him, but his report in 1901 of the burn caused when he carried an active sample of the Curies' radium in his vest pocket inspired investigation by physicians, leading ultimately to medical use.
For his discovery of radioactivity, Becquerel shared the 1903 Nobel Prize for Physics with the Curies; he was also honoured with other medals and memberships in foreign societies. His own Academy of Sciences elected him its president and one of its permanent secretaries.
Lawrence Badash CitationsMLA Style:
"Henri Becquerel." Encyclopædia Britannica. 2009. Encyclopædia Britannica Online. 22 Sep. 2009APA Style:
Henri Becquerel. (2009). In Encyclopædia Britannica. Retrieved September 22, 2009, from Encyclopædia Britannica Online: http://www.britannica.com/EBchecked/topic/58020/Henri-BecquerelHenri Becquerel discovered in 1896 the natural radioactivity.
NO. Henri Becquerel was the discoverer of radioactivity.
Radioactivity was first discovered in 1896 by the French scientist Henri Becquerel.
March 1, 1896: Henri Becquerel Discovers Radioactivity
Radioactivity was discovered during 1896 by Henri Becquerel, who was a French scientist when he was working on phosphorescent materials. Other research was done by Becquerel, Ernest Rutherford, Paul Villard, Pierre Curie, Marie Curie, and others afterwards.
Henri Becquerel discovers the radioactivity.
Henri Becquerel discovered radioactivity
Henri Becquerel was born on December 15, 1852.
Henri Becquerel was born on December 15, 1852.
Antoine Henri Becquerel was born on 15 December 1852.
Henri Becquerel died on August 25, 1908 at the age of 55.
Henri Becquerel died on August 25, 1908 at the age of 55.
Henry Becquerel discovered radio-activity.
Henri Becquerel discovered in 1896 the natural radioactivity.
Henri becquerel
Antoine Henri Becquerel won The Nobel Prize in Physics in 1903.
Henri Becquerel was born on December 15, 1852 and died on August 25, 1908. Henri Becquerel would have been 55 years old at the time of death or 162 years old today.