In the molecule $CH \equiv C - CH = CH_2$,the hybridisation of the $C - C$ single bond is:

The compound having both $sp$ and $sp^{2}$ hybridised carbon atoms is

$CH_3-CH_2-CH=CH_2$ has hybridisation

Consider a positively charged $C_2H_3$ species in which the positively charged carbon is $sp$-hybridized,the uncharged carbon is $sp^2$-hybridized and an empty $p$-orbital is perpendicular to the $\pi$ system. What is the best description of this cation?

The total number of $\pi-$bond electrons in the following structure is

Which of the following represents the given mode of hybridisation $sp^2-sp^2-sp-sp$ from left to right?