Question

What are the electron geometry and the molecular geometry of water?

Answer 1

The electronic geometry gives water a tetrahedral shape.
The molecular geometry gives water a bent shape.

Explanation:

Electronic geometry takes into account the electron pairs that are not participating in bonding, and the electron cloud density.

Here the 2 bonds of hydrogen count as 2 electron clouds, and the 2 electron pairs count as another 2, giving us a total of 4. With 4 electron regions, the VSEPR electronic geometry is tetrahedral.

Molecular geometry looks at only those electrons that are participating in bonding. So here, only the 2 bonds to H are taken into account.

The shape would not be linear, as in the case with `"CO"_2`, even though there are only 2 bonds in `"H"_2"O"` due to the fact that the unpaired electrons would not allow such a shape.

There is electron repulsion going on so electrons take on shapes that help to reduce electron repulsion.