Why is the ammonia molecule sp^3-"hybridized" even though there are only 3xxN-H bonds?

1 Answer
Jun 15, 2017

Because there are 4 electron pairs around the central nitrogen atom.........

Explanation:

Nitrogen has 5 valence electrons, and it forms 3xxsigma-"bonds" with the hydrogen atoms, which each contribute "1 electron".

Because there are FOUR electron pairs around the central nitrogen atom, VESPER predicts tetrahedral geometry with respect to the disposition of the electron pairs. But because we describe molecular geometry on the basis of atoms NOT on electron pairs.....the geometry of ammonia descends from tetrahedral to trigonal pyramidal, and this treatment is in actual accord with the OBSERVED geometry.

/_H-N-H~=104-5^@