The number of bridging $CO$ ligands in $[Mn_{2}(CO)_{10}]$ is $....$ .

What are metal carbonyls? Give examples.

What is the nature of the $Fe-C$ bond in $Fe(CO)_5$?

Select the true statement from the following for metal carbonyls?

The bond length of the $C-O$ bond in carbon monoxide is $1.128 \ \mathring{A}$. The $C-O$ bond length in $Fe(CO)_5$ is ............. $\mathring{A}$.

The molecular formula of Wilkinson catalyst,used in the hydrogenation of alkenes is -