The transition metals generally form complex compounds due to:
(A) Variable oxidation states
(B) High ionic charges
(C) Smaller size of metal ion
(D) Metallic conductivity
(E) Availability of d-orbitals
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → (B), (C), and (E) only
A complex is formed when a metal ion accepts lone pairs of electrons from a number of ligands (anions or neutral molecules).
(A) Variable oxidation states — Incorrect. Variable oxidation states explain the catalytic and redox behaviour of these metals; they are not the reason for complex formation.
(B) High ionic charges — Correct. A highly charged ion attracts the ligands strongly.
(C) Smaller size of metal ion — Correct. A small ion has a high charge density.
(D) Metallic conductivity — Incorrect. Conductivity is a property of the metal in bulk and has nothing to do with bonding to ligands.
(E) Availability of d-orbitals — Correct. Vacant d orbitals receive the ligand lone pairs.
NCERT (2026-27 edition):
Formation of Complex Compounds
