Chemistry - CHEMICAL BONDING Question with Solution | TestHub

(B) Correct: $(H_{3}Si{)}_{3}N$ is planar due to $p\pi -d\pi$ back-bonding where nitrogen's lone pair is delocalized into silicon's vacant d-orbitals; $(Si{H}_3{)}_{3}P$ is pyramidal because phosphorus is larger and back-bonding is negligible.

(C) Correct: $C{H}_3-NCS$ is bent because the nitrogen lone pair is localized, whereas $Si{H}_3-NCS$ is linear due to back-bonding between N and Si.

(D) Correct: $(C{H}_3{)}_{3}N$ is pyramidal (standard $s{p}^3$ with lone pair repulsion), but $(Ge{H}_3{)}_{3}N$ is planar because germanium, like silicon, allows for back-bonding from nitrogen.

(A) Incorrect: Both $[B_3{O}_6{]}^{3-}$ and $B_3{N}_3{H}_6$ (borazine) possess planar ring structures.