Transition Metal (or Transition Element) meanings are 1) The IUPAC definition defines a Transition Metal as “an element whose atom has a partially filled d sub-shell, or which can give rise to cations with an incomplete d sub-shell”; 2) Many scientists describe a “transition metal” as any element in the d-block of the periodic table, which includes groups 3 to 12 on the periodic table. In actual practice, the f-block lanthanide and actinide series are also considered transition metals and are called “inner transition metals”.
Related Definitions in the Project: The Element and Substance
