* Silicon (Si) has 4 valence electrons.
* Each hydrogen (H) atom has 1 valence electron.
* To form SiH4, silicon needs to form 4 single bonds with 4 hydrogen atoms.
To accommodate these 4 bonds, silicon needs 4 orbitals. It achieves this by hybridizing its one 3s orbital and its three 3p orbitals, forming four equivalent sp3 hybrid orbitals. Each of these hybrid orbitals then overlaps with the 1s orbital of a hydrogen atom to form a sigma bond.
Therefore, the hybridization of SiH4 is sp3, resulting in a tetrahedral molecular geometry.
