linear
generic formula: AX2
example: beryllium chloride BeCl2, acetylene HCCH
The molecular geometry will match the electronic geometry of linear. The bond angle is 180° and there is no reason to tweak the bond to another value.
POLARITY: NON-POLAR - As long as both positions have the same atom, then the molecule cannot be polar due to perfect symmetry.
no such thing
There is no point in discussing the "geometry" of only 2 atoms. Yes, it is linear except that there is no defined bond angle. You have to have at least 3 atoms to define an angle, just like in geometry class you needed three points to define an angle. Therefore there is no name here or geometry.