What is the elements of second transition series?

                            

• The ten elements from yttrium to cadmium (Z=39 to 48) constitute the second transition series.
• In yttrium, 4d subshell begins filling up and its outer electronic configuration is 4d1 5s2.
• The filling up of the 4d orbitals continues as we keep moving in this period towards the next nine elements, namely, zirconium(Z=40) niobium(Z=41), molybdenum(Z=42), technetium(Z=43), ruthenium(Z=44), rhodium(Z=45), palladium(Z=46), silver(Z=47), and cadmium(Z=48).
• In cadmium(Z=48) the 4d subshell has now the maximum permissible number of 10 electrons, the configuration of the outer shell being 4d10 5s2.
• According to the definition of d block elements already given, the nine elements from Y to Ag, may be taken as constituting the Second series of d block elements.
• The definition, based on the number of electron in the 4d subshell excludes Cd from second transition series.