What is molecular geometry?
Molecular geometry is a way of describing the shapes of molecules. It applies a theory called VESPR for short.
VESPR stands for valence shell electron pair repulsion. This theory basically says that bonding and non-bonding electron pairs of the central atom in a molecule will repel (push away from) each other in three dimensional space and this gives the molecules their shape.
We can use the following notations when examining a Lewis structure of a molecule.
A = central atom
X = peripheral atoms
E = non-bonding electron pairs of the central atom
Here are some examples: