Amalgams are:

An example of a $\sigma$-bonded organometallic compound is:

Which of the following compounds is not considered an organometallic compound?

Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$.
Assertion $(A)$: The metal-carbon bond in metal carbonyls possesses both $\sigma$ and $\pi$ character.
Reason $(R)$: The ligand-to-metal bond is a $\sigma$ bond and metal-to-ligand bond is a $\pi$ bond.
In the light of the above statements,choose the most appropriate answer from the options given below :

The Wilkinson catalyst is

Which statement is true for ferrocene?