phil elverum twitter|@PWElverum : iloilo The general electronic configuration of the Lanthanide element is [Xe] 4f 1-14 5d 10-1 6s 2. Since the inner electron level, 4f orbitals are successively filled from (4f 1 to 4f 14) though there are outer incompletely filled electron levels, these elements are called inner transition elements and the series are called inner transition series.
phil elverum twitter,