Question

The planar shape of N(SiH${}_3{)}_3$ is explained by the:

• A. type of hybrid orbitals of nitrogen
• B. additional $d\pi -p\pi$ overlap along the $N-Si$ bond
• C. higher electronegativity of nitrogen
• D. higher electronegativity of silicon

Answer 1

Answer: (A), (B)

The correct options are
A type of hybrid orbitals of nitrogen
B additional $d\pi -p\pi$ overlap along the $N-Si$ bond

In $N(Si{H}_3{)}_3$, $Si$ has vacant d-orbital which facilitates the $d\pi -p\pi$ overlap along the $N-Si$ bond so nitrogen has $s{p}^2$ hybridization with trigonal planar shape.
Higher electronegativity of nitrogen, sigma and pi bonds are not responsible for planarity of the molecule.
Hence, options A & B are correct.