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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.
The actinides derive their name from the group 3 element actinium. The informal chemical symbol An is used in general discussions of actinide chemistry to refer to any actinide. All but one of the actinides are f-block elements, corresponding to the filling of the 5f electron shell; lawrencium, a d-block element, is also generally considered an ...
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A minor actinide is an actinide, other than uranium or plutonium, found in spent nuclear fuel. The minor actinides include neptunium (element 93), americium (element 95), curium (element 96), berkelium (element 97), californium (element 98), einsteinium (element 99), and fermium (element 100). [ 2 ]
The actinide concept explained some of the observed properties of the first few actinides, namely the presence of +4 to +6 oxidation states, and proposed hybridization of the 5f and 6d orbitals, whose electrons were shown to be loosely bound in these elements. It also supported experimental results for a trend towards +3 oxidation states in the ...
As with most lanthanides and many actinides, actinium assumes oxidation state +3 in nearly all its chemical compounds. Actinium is found only in traces in uranium and thorium ores as the isotope 227 Ac, which decays with a half-life of 21.772 years, predominantly emitting beta and sometimes alpha particles , and 228 Ac, which is beta active ...
In fact, the 5f subshells of the actinides have a larger spatial extent than the 4f orbitals of the lanthanides and thus actinide compounds have greater covalent character than the corresponding lanthanide compounds, leading to a more extensive coordination chemistry for the actinides than the lanthanides. [4]
Actinidine is an iridoid produced in nature by a wide variety of plants and animals. It was the first cyclopentanoid monoterpene alkaloid to be discovered. [2] It is one of several compounds that may be extracted from the valerian (Valeriana officinalis) root [3] and silver vine (Actinidia polygama), as well as several types of insects in the larval and imaginal stages. [4]