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The actinide series derives its name from the first element in the series, actinium. The informal chemical symbol An is used in general discussions of actinide chemistry to refer to any actinide. [1] [2] [3] The 1985 IUPAC Red Book recommends that actinoid be used rather than actinide, since the suffix -ide normally indicates a negative ion.
Protactinium is an actinide positioned in the periodic table to the left of uranium and to the right of thorium, and many of its physical properties are intermediate between its neighboring actinides. Protactinium is denser and more rigid than thorium, but is lighter than uranium; its melting point is lower than that of thorium, but higher than ...
Protactinium(V) fluoride can be prepared by reacting protactinium oxide with either bromine pentafluoride or bromine trifluoride at about 600 °C, and protactinium(IV) fluoride is obtained from the oxide and a mixture of hydrogen and hydrogen fluoride at 600 °C; a large excess of hydrogen is required to remove atmospheric oxygen leaks into the ...
The actinides encompasses the 15 chemical elements that lie between actinium and lawrencium on the periodic table. ... Protactinium (2 C, 2 P) T. Thorium (2 C, 28 P) U.
Most tetravalent actinides react similarly to form actinocenes: Bis(cyclooctatetraene)protactinium was first prepared in 1973 by turning protactinium(V) oxide into the pentachloride and reducing it with aluminium powder before reacting it with potassium cyclooctatetraenide. [7] +
As with most lanthanides and actinides, actinium exists in the oxidation state +3, and the Ac 3+ ions are colorless in solutions. [25] The oxidation state +3 originates from the [Rn] 6d 1 7s 2 electronic configuration of actinium, with three valence electrons that are easily donated to give the stable closed-shell structure of the noble gas ...
Actinides vs. fission products ... and in doing so, it transmutes into protactinium-234. 234 Th has a mass of 234.0436 atomic mass units, ...
While the later actinides from americium onwards are predominantly trivalent and behave more similarly to the corresponding lanthanides, as one would expect from periodic trends, the early actinides up to plutonium (thus including thorium and uranium) have relativistically destabilised and hence delocalised 5f and 6d electrons that participate ...