Which one of the following pairs is isostructural ($i.e.$,having the same shape and hybridization)?

Fill in the blanks:
$(i)$ Based on the type of overlapping,covalent bonds are classified into ........ and .......... .
$(ii)$ The bond formation involving hybrid orbitals is called ............. .
$(iii)$ The type of hybridization observed in the $C_2H_6$ molecule is ........... .
$(iv)$ The type of hybridization observed in the $BrF_5$ complex is ............... .

Observe the following reactions. Identify the reaction in which the hybridisation of the underlined atom is changed.

Which of the following statements is incorrect?

Bond $X$ is formed by the overlap of which type of hybridized orbitals?

In which of the following cases $C-C$ bond length will be highest?