Question

What is the Lewis dot diagram for `H_2O`?

Answer 1

Well we have 6 valence electrons from the oxygen atom......

Explanation:

And 2 valence electrons from the hydrogen atom. And thus we have to distribute 4 electron pairs around the central oxygen atom. VESPER predicts that these 4 electron pairs will assume the shape of a tetrahedron:

The `"electronic geometry"` is tetrahedral to a first approximation. The `"molecular geometry"` is bent with `/_H-O-H~=104.5^@`; the (non-bonding) lone pairs are closer to the oxygen atom, and these tend to compress `/_H-O-H` down from the ideal tetrahedral angle of `109.5^@`.