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protactinium
Book article from: The Columbia Encyclopedia, Sixth Edition
protactinium , radioactive chemical element; symbol...calculated); valence +4, +5. Protactinium is a malleable, shiny silver-gray...and a pentoxide (Pa 2 O 5 ). Protactinium has 24 isotopes of which only three...
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Periodic Table of the Elements: Protactinium
Book article from: The Columbia Encyclopedia, Sixth Edition
Periodic Table of the Elements: Protactinium Periodic Table of the Elements: Protactinium Atomic Number: 91 Atomic Symbol: Pa Protactinium Atomic Weight: 231.0359 Electron Configuration: 2 · 8&thinsp...
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Actinides
Encyclopedia entry from: The Gale Encyclopedia of Science
...members are: actinium, thorium, protactinium, uranium, neptunium, plutonium...atomic symbol, Ac), thorium (Th), protactinium (Pa), and uranium (U) are extracted...Africa, and Namibia, thorium and protactinium are available in large quantities...
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actinide series
Book article from: The Columbia Encyclopedia, Sixth Edition
...members are (in order of increasing atomic number) thorium , protactinium , uranium , neptunium , plutonium , americium , curium...plutonium have been found in uranium ores. Actinium and protactinium are found in nature as decay products of some thorium and...
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thorium
Book article from: The Columbia Encyclopedia, Sixth Edition
...thorium-233, emitting a gamma ray. Thorium-233 decays (half-life about 22 min) to protactinium-233, emitting a beta particle. The protactinium-233 decays (half-life about 27 days) with another beta particle emission to uranium...
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uranium
Book article from: The Columbia Encyclopedia, Sixth Edition
...parent substance of the so-called actinium series, a 15-member radioactive decay series ending in stable lead-207; protactinium-231 and actinium-227 are the relatively stable members of this series. Because the rate of decay in these series is...
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Hahn, Otto
Book article from: World Encyclopedia
...William Ramsay and Ernest Rutherford . In 1906, he returned to Germany to work with Lise Meitner. In 1917, they discovered protactinium . Hahn and Meitner investigated Enrico Fermi's work on the neutron bombardment of uranium . He received the 1944 Nobel...
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Elements
Book article from: The Columbia Encyclopedia, Sixth Edition
...potassium K 19 39.0983 63.25 760. praseodymium Pr 59 140.9077 931. 3512. promethium Pm 61 (145) 1042 3000. (est.) protactinium Pa 91 231.0359 <1600. 4026. radium Ra 88 226.0254 700. 1140. radon Rn 86 (222) -71. -61.8 rhenium Re...
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Pa
Book article from: The Columbia Encyclopedia, Sixth Edition
Pa symbol for the element protactinium .
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Lise Meitner
Book article from: The Columbia Encyclopedia, Sixth Edition
...the Nobel Institute at Stockholm. In 1917, working with Otto Hahn , she isolated the most stable isotope of the element protactinium ; she also investigated the disintegration products of radium , thorium , and actinium and the behavior of beta rays. In...
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