Pariod numbers: periodicity

The period number is an identifier used to describe the row of the standard periodic table in which the element appears.

The lanthanoids and actinoids are extensions of Periods 6 and 7 respectively, hence their assignment to those Periods.





Literature sources

  1. International Union of Pure & Applied Chemistry: Commission on the Nomeclature of Inorganic Chemistry, Nomenclature of Inorganic Chemistry Recommendations 1990, Ed. G.J. Leigh, Blackwell Science, Oxford, 1990.
  2. W.C. Fernelius, and W.H. Powell, "Confusion in the periodic table of the elements", J. Chem. Ed., 1982, 59, 504-508.
  3. Periodic table in any volume of the Inorganic Oxford Chemistry Primers, Oxford University Press, Oxford, UK.

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