# What is the molecular geometry of a molecule with 2 outer atoms and 1 lone pair on the central atom?

Jul 22, 2017

This is a bent molecule.

#### Explanation:

The image above shows the molecular geometries of different situations according to the VSEPR (Valence Shell Electron-Pair Repulsion) theory.

In the first column, the steric number is the number of atoms bonded to the cental atom plus the number of lone electron pairs about the central atom.

In our situation, we're asked to find the geometry of a molecule with color(red)("two atoms" bonded to the central atom and color(green)("one lone pair" about the central atom, so the steric number of this molecule is

color(red)(2) + color(green)(1) = color(blue)(3

Thus, there are only two options for the molecular geometry of this molecule: trigonal planar, in which there are $0$ lone pairs, or bent (angular), which there is $1$ lone pair.

Since our molecule has color(green)("one lone pair" about the central atom, this is a bent molecule.