Look up: actinide

1. Actinide
   Elements 89-102 are called actinides. Electrons added during the Aufbau construction of actinide atoms go into the 5f subshell. Actinides are unstable and undergo radioactive decay. The most common actinides on Earth are uranium and thorium.HHeLiBeBCNOFNeNaMgAlSiPSClArKCaScTiVCrMnFeCoNiCuZnGaGeAsSeB...
   Found on http://www.diracdelta.co.uk/science/sour
   
   
2. Actinide
   An element with atomic number of 89 (actinium) to 102. Usually applied to those above uranium - 93 up (also called transuranics). Actinides are radioactive and typically have long half-lives. They are therefore significant in wastes arising from nuclear fission, e.g. used fuel. They are fissionable in a fast reactor
   Found on http://www.encyclo.co.uk/local/20725
   
   
3. actinide
   Elements 89-102 are called actinides. Electrons added during the Aufbau construction of actinide atoms go into the 5f subshell. Actinides are unstable and undergo radioactive decay. The most common actinides on Earth are uranium and thorium.
   Found on http://antoine.frostburg.edu/chem/senese
   
   
4. Actinide
   an element with atomic number of 89 (actinium) or above111.
   Found on http://www.encyclo.co.uk/visitor-contrib
   
   
5. actinide
   The group of elements,from actinium(atomic number 89)to lawrencium(atomic number 103),which together occupy one position in the periodic table.The series includes the naturally occurring and man-made isotopes of thorium and uranium and of the higher actinides such as neptunium,plutonium,americium an...
   Found on http://www.mijnwoordenboek.nl/definition
   
   
6. actinide
   <chemistry> Any element in the periodic table which has an atomic number between 89 and 103. ... (09 Oct 1997) ...
   Found on http://www.mondofacto.com/facts/dictiona
   
   
7. Actinide
   The actinide or actinoid (IUPAC nomenclature) series encompasses the 15 metallic chemical elements with atomic numbers from 89 to 103, actinium through lawrencium. The actinide series derives its name from the group 3 element actinium. All but one of the actinides are f-block elements, correspondin...
   Found on http://en.wikipedia.org/wiki/Actinide
   
   
8. actinide
   Actinides element Z outermost electrons valences actinium (Ac) 89 6d¹7s² 3 thorium (Th) 90 6d²7s² 4 protactinium (Pa) 91 5f²6d¹7s² 4...
   Found on http://www.daviddarling.info/encyclopedi
   
   
9. Actinide
   An actinide is an element with an atomic number between 89 and 103.
   Found on http://www.probertencyclopaedia.com/brow
   
   
10. actinide
    Any of a series of 15 radioactive metallic chemical elements with atomic numbers 89 (actinium) to 103 (lawrencium). Elements 89 to 95 occur in nature; the rest of the series are synthesized elements only. Actinides are grouped together because of their chemical similarities (for example, they are all bivalent), the properties differing only sli...
    Found on http://www.talktalk.co.uk/reference/ency