$CH_3MgBr$ is an organometallic compound because ....

Which is not true about metal carbonyls?

The formula of ferrocene is:

Which of the following is a $\sigma$ and $\pi$ bonded 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 number of bridging $CO$ ligands in $[Mn_{2}(CO)_{10}]$ is $....$ .