Electron Configurations of the Transition Metals
and Their Ions
As with all the elements, the properties of the transition elements and their compounds
arise largely from the electron configurations of their atoms (Section 8.2) and ions
(Section 8.4). As Figure 23.1 shows, d-block (B-group) elements occur in four series
that lie within Periods 4 through 7 between the last ns-block element [Group 2A(2)]
and the first np-block element [Group 3A(13)]. Each of the four series contains ten
elements based on the filling of five d orbitals, for a total of 40 transition elements.
Lying between the first and second members of the series in Periods 6 and 7 are the