Question

Equilateral shape has which hybridisation?

Answer 1

Hint : Hybridisation is the concept that says that atomic orbitals undergo fusion to produce newly hybridized orbitals. This process alters their physical and structural properties. This leads to the change in shape.

Complete Step By Step Answer:
So, Hybridized orbitals are the mixture of atomic orbitals superimposed on each other.
To calculate the hybridisation and its associated shape, one has to look for the Lewis structure of the molecule.
Then concentrate on the number of lone pairs of electrons and the number of surrounding atoms or bonds that particular atom shares.
Also, we know that according to VSEPR theory i.e. valence Shell Electron pair repulsion theory the lone pairs of electrons repel each other so to minimize the repulsion, largest possible angles are made between the bonds or the lone pairs.
In $s{p^2}$ hybridisation , one $2s$ orbital and two $2p$ orbitals overlap each other to form hybridized three $sp$ orbitals and each of them has $67\%$ of $p$ character and $33\%$ of $s$ character .
The frontal lobes align themselves in the form of corners of triangles resembling the planar triangular structure. This shape is to minimize the maximum repulsion and have an energetically stable geometrical structure.
While the remaining $p$ orbitals adjust themselves perpendicular to these three hybridized orbitals.
Hence, the answer to our question is $s{p^2}$ hybridisation.
Therefore, Equilateral shape has $s{p^2}$ hybridisation.

Note :
There are different types of intermixing of orbitals that give rise to different types of hybridisation, they all are developed to explain the geometrically stable structure after theories like VBT – Valence Bond theory failed to explain.