What is the Lewis dot diagram for H_2O?

May 30, 2017

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 $\text{electronic geometry}$ is tetrahedral to a first approximation. The $\text{molecular geometry}$ is bent with $\angle H - O - H \cong {104.5}^{\circ}$; the (non-bonding) lone pairs are closer to the oxygen atom, and these tend to compress $\angle H - O - H$ down from the ideal tetrahedral angle of ${109.5}^{\circ}$.