Show the polarisation of the carbon-magnesium bond in the following structure: $CH_3-CH_2-CH_2-CH_2-MgX$.

Fill in the blanks:
$(1)$ In $+E$ effect,$\pi$ electrons from a multiple bond migrate to the ........... .
$(2)$ In $-E$ effect,$\pi$ electrons from a multiple bond migrate to the ........... .
$(3)$ ........... and ........... increase stability.
$(4)$ ........... inductive effect increases the acidic strength and ........... inductive effect decreases the strength of $-COOH$.

Define the electromeric effect and describe its types.

Which of the following groups does not show $(-R)$ effect?

In $CH_3(3) - CH_2(2) - CH_2(1) - Cl$,give the increasing order of the inductive effect for carbon atoms $1, 2,$ and $3$.

Which types of electronic effects are seen in the structure of a molecule?