Why Are Lanthanides and Actinides Excluded from the Periodic Table?

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The discussion centers on the exclusion of the lanthanide and actinide series from the main body of the periodic table, questioning their placement and the concept of non-periodicity among these elements. It highlights that the f-block elements currently lack group numbers, which may change in the future, and notes that group assignments are largely conventional. The format of the periodic table is described as arbitrary, shaped by human tendencies to categorize, rather than a strict reflection of natural groupings. This suggests that while the periodic table is a valuable model for understanding elements, it may not fully capture the complexities of their relationships in nature. Alternative periodic tables are also mentioned as different ways to represent elemental relationships.
faiz4000
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why aren't the lanthanide and actinide series included in the periodic table? is there some non periodicity in there elements?
 
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Are you asking why these series are shown at the bottom? It's a http://en.wikipedia.org/wiki/Extended_periodic_table" .
 
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yes,i am trying to say why they are not in the main periodic table? why you can't assign there elements to any group? Is there any non-periodicity in the elements?
 
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faiz4000 said:
why aren't the lanthanide and actinide series included in the periodic table? is there some non periodicity in there elements?

The format of the periodic table is "arbitrary," not in the sense that it makes no sense, but from a Sociology/Psychology of Science perspective in the sense that the manner in which it is presented is guided by the human tendency to categorize in groups with linkage to other areas of human understanding. How we, as products of nature, group the elements may or may not be how nature in its raw form groups them (most likely not...). In other words, our periodic table is an imperfect, but extremely useful model. There are others. See...

Alternative Periodic Tables
http://en.wikipedia.org/wiki/Alternative_periodic_tables
 
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