In allene $(C_3H_4)$,the type of hybridization of the carbon atoms is (are)

Explain the formation of four sigma bonds by $sp^3$ hybrid orbitals with an example.

The species in which the nitrogen atom is in a state of $sp$ hybridisation is

The carbon atoms in an acetylene molecule are in which state of hybridisation?

In which of the following combinations does the hybridisation of the central atom $(^*)$ $NOT$ change?

The number of molecules/ions from the following in which the central atom is involved in $sp^3$ hybridization is: $NO_3^{-}, BCl_3, ClO_2^{-}, ClO_3$