Question

Assertion (A) Transition metals form a large number of complex compounds.
Reason (R) It happens due to the comparatively smaller size of the metal ions only.

• A. Both $A$ and $R$ are correct; $R$ is the correct explanation of $A$.
• B. Both $A$ and $R$ are correct; $R$ is not the correct explanation of $A$.
• C. $A$ is correct; $R$ is incorrect.
• D. $R$ is correct; $A$ is incorrect.

Answer 1

Answer: (C)

Complex compounds are those in which the metal ions bind a number of anions or neutral molecules giving complex species with characteristic properties.
$\text{ e.g. }{\left[Fe(CN{)}_6\right]}^{3-},{\left[Fe(CN{)}_6\right]}^{4-}\text{. }$
Transition metals form a large number of complex compounds due to comparatively smaller sizes of the metal ions, their high ionic charges and the availability of $d$-orbitals for bond formation.