Look up: Actinides

1. 
   Actinides
   Elements 90 to 103 (after actinium)
   Found on http://home.nas.net/~dbc/cic_hamilton/di
   
   
2. 
   Actinides
   Actinides are a group of Nuclides including thorium , protactinium , uranium , neptunium , plutonium , americium , curium , californium etc. Only thorium, uranium, plutonium, americium and californium are probably significant as the others are only produced artificially and have a relatively short Half-Life . For the others, they all have much longer half-life's (e.g. plutonium-239 is in excess of 24,000 years) and are all Alpha Emitters . This means they have the potential to cause a significant Internal Radiation hazard through Inhalation and Ingestion .
   Found on http://www.ionactive.co.uk/glossary_atoz
   
   
3. 
   Actinides
   Elements 89 to 103 (between lawrencium and actinium) on the periodic table. Only the first four have been found in nature in appreciable amounts. The remainder have been produced synthetically.
   Found on http://www.allchemicals.info/index/actio
   
   
4. 
   Actinides
   This is a group of elements within the periodic table and are also known as the transuranics. The name refers to those elements with increasing atomic no. from actinium, which all have similar chemical properties, like the lanthanides. The first few members of the group are the naturally occuring elements actinium, thorium, proactinium and uranium. Beyond this elements have been made artificially by radioactive bombardment. These artificial elements are unstable, some have very short lifeimes and undergo spontaneous radioactive decay.
   Found on http://www.ch.ic.ac.uk/vchemlib/mol/glos
   
   
5. 
   actinides
   The actinides (actinons or actinoids) are the fourteen elements from thorium to lawrencium inclusive, which follow actinium in the periodic table. The position of actinium is somewhat equivocal and, although not itself an actinide, it is often included with them for comparative purpose. The series includes the following elements: thorium (Th), prot...
   Found on http://www.ktf-split.hr/periodni/en/abc/
   
   
6. 
   Actinides
   This is a group of elements within the periodic table and are also known as the transuranics. The name refers to those elements with increasing atomic no. from actinium, which all have similar chemical properties, like the lanthanides. The first few membe
   Found on http://www.chemicalglossary.net/definiti
   
   
7. 
   actinides
   Those elements with atomic numbers 89 to 103, corresponding to the lanthanides in the Periodic Table. ... Synonym: actinide elements. ... Origin: actinium, first element of the series ... (05 Mar 2000) ...
   Found on http://www.mondofacto.com/facts/dictiona
   
   
8. 
   actinides
   Those elements with atomic numbers 89 to 103, corresponding to the lanthanides in the Periodic Table. Syn: actinide elements [actinium, first element of the series]
   Found on http://www.stedmans.com/section.cfm/45