4d series can be represented by
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Y to Cd (Y = Yttrium & Cd = Cadmium)
The d-block has four series, in which the 3d, 4d, 5d and 6d orbitals are filled. The 4d series (second transition series) runs from yttrium (Z = 39), the first element to put an electron into 4d, to cadmium (Z = 48), where 4d is completely filled (4d105s2).