The Ziegler-Natta catalyst is

The organometallic compound $(CH_3)_3 CMgBr$ on reaction with $D_2 O$ produces . . . . . . .

Given below are two statements:
Statement $I$: The $M - C \sigma$ bond is formed by the donation of a lone pair of electrons on the carbonyl carbon into a vacant orbital of the metal.
Statement $II$: The $M - C \pi$ bond is formed by the donation of a pair of electrons from a filled $d$-orbital of the metal into the vacant antibonding $\pi^*$ orbital of carbon monoxide.
In the light of the above statements, choose the correct answer from the options given below:

The compound that is not an olefinic organometallic compound is:

What is the chemical formula of Tartar Emetic?

Discuss the nature of bonding in metal carbonyls.