Question

Explain the hybridisation taking place in $H_{2}O$ molecule, which is responsible for its bond formation.

Answer 1

The electronic configuration of oxygen atom is 1s² 2s² 2p⁴. Therefore, for bond formation, one s-orbital (2s) and three p-orbitals ( $2p_x$, $2p_y$ and $2p_z$ ) intermix and redistribute into four identical sp³ orbitals of equal energies and shape.
This leads to sp³ hybridisation in $H_{2}O$ molecule.

Now we have four sp³ hybridised orbitals, where 2 orbitals already have paired electrons, while 2 orbitals are having single electron each. These 2 sp³ hybridised orbitals having single electron each overlap with s-orbital of 2 hydrogen atoms forming 2 covalent bonds.