Define the following terms:
$(i)$ Hybridisation
$(ii)$ $sp$ Hybridisation
$(iii)$ $sp^2$ Hybridisation
$(iv)$ $sp^3$ Hybridisation
$(v)$ Hydrogen bonding

(N/A) $(i)$ Hybridisation: The process of intermixing of the orbitals of slightly different energies so as to redistribute their energies,resulting in the formation of a new set of orbitals of equivalent energies and shape.
$(ii)$ $sp$ Hybridisation: The mixing of one $s$ and one $p$ orbital to form two equivalent $sp$ hybrid orbitals,resulting in a linear geometry with a bond angle of $180^{\circ}$.
$(iii)$ $sp^2$ Hybridisation: The mixing of one $s$ and two $p$ orbitals to form three equivalent $sp^2$ hybrid orbitals,resulting in a trigonal planar geometry with a bond angle of $120^{\circ}$.
$(iv)$ $sp^3$ Hybridisation: The mixing of one $s$ and three $p$ orbitals to form four equivalent $sp^3$ hybrid orbitals,resulting in a tetrahedral geometry with a bond angle of $109.5^{\circ}$.
$(v)$ Hydrogen bonding: The attractive force which binds a hydrogen atom of one molecule with an electronegative atom (like $F, O, N$) of another molecule.