Linear
Molecules with 2 VSEPR pairs adopt a linear VSEPR shape.
CO2 is an example of a molecule with the VSEPR formula AX2. The VSEPR shape is linear and the molecule is linear, with an X-A-X angle of 180◦ at the central carbon atom. That is, the angle between each oxygen atom, denoted X, and the central carbon atom, denoted A, is 180◦. There are two VSEPR pairs, because n=2 and m=0, and therefore n+ m = 2.
If one of the positions is occupied by a lone pair, the VSEPR formula is AXE. There are two VSEPR pairs, because n=1 and m=1, and therefore n+ m = 2. The VSEPR shape is linear and the molecular shape is linear.