Although successive replacement of bonded atoms X by nonbonding electron pairs does not change the arrangement of electron pair domains about atom A, it does change the shape because shape is a description of the location of the outer atoms.
The various shape descriptors are shown below for the molecules of type AXn where the sum of the number of bonded atoms and the number of non-bonding pairs at A is either three or four. X is an atom and E is a nonbonding electron pair.
The diagrams show the three-dimensional arrangement of bonds.
Those atoms joined to the central atom by a
The various shape descriptors are shown below for the molecules of type AXn where the sum of the number of bonded atoms and the number of non-bonding pairs at A is either three or four. X is an atom and E is a nonbonding electron pair.
| Trigonal planar family | |
| AX3 | AX2E |
 |  |
| trigonal planar | bent |
| Tetrahedral family | ||
| AX4 | AX3E | AX2E2 |
 |  |  |
| tetrahedral | trigonal pyramid | bent |
The diagrams show the three-dimensional arrangement of bonds.
Those atoms joined to the central atom by a
solid line (—) are in the plane of the screen.
solid wedge (
) point to atoms in front of the plane of the screen.
hashed wedge (
) point to atoms behind the plane of the screen.
solid wedge (
) point to atoms in front of the plane of the screen.hashed wedge (
) point to atoms behind the plane of the screen.