According to valence bond theory, which orbitals on n and h overlap in the nh3 molecule? 2s on n overlaps with 1s on h 2p on n overlaps with 1s on h sp3 on n overlaps with 1s on h sp3 on n overlaps with sp on h 2p on n overlaps with 2s on h

Answer is: sp3 on nitrogen overlaps with 1s on hydrogen.
Electron configuration for nitrogen: ₇N 1s² 2s² 2p³.
Electron configuration for hydrogen: ₁H 1s¹.
The central atom in ammonia, nitrogen, is sp3 hybridized (one s and three p-orbitals will combine for a four sp3 hybridized orbitals), because sp3 orbitals have lower energy.