An electron-precise hydride is a type of hydride which has the exact number of electrons required to form normal covalent bonds, no excess no deficient. These are formed generally by group 14 elements like Si and C which have 4 valence electrons.

Eg. CH₄ , SiH₄, etc.

Due to the sp³ hybridisation configuration, the molecular geometry is tetrahedral.

sp³ hybridisation is tetrahedral in geometry.

Tetrahedral geometries of CH₄ and SiCl₄.

B₂H₆ is an electron deficient hydride. These have an incomplete octet. They are formed generally by the group 13 elements like B, Al, etc.