Consider a 3-atom molecule A-B-A for which B has a total of only four valence electrons, enough to make two bonds. Predict the A-B-A bond angle.
Molecular Geometry:
Most covalent molecules contain at least 3 constituent atoms, such that the concept of molecular geometry can be applied. This is the three-dimensional arrangement of some number of peripheral atoms, that are bonded to the same central atom. The geometry is directly derived from VSEPR theory applied to the valence electron distribution on the central atom, which may potentially contain some number of non-bonding valence electron pairs. Each geometry has its own set of bond angles. These are the angles for an "A-B-A" linkage, where "B" is the central atom and "A" are peripheral atoms.