Final answer:
A central atom bonded to only two atoms will adopt a linear geometry regardless of bond type. This linear shape arises due to the electron groups arranging 180° apart to minimize repulsion. Examples include BeH2 and CO2.
Step-by-step explanation:
Regardless of whether the bonds are single, double or triple, a central atom with only two atoms bonded to it will take the linear geometry. Double or triple bonds are counted as one electron group, and any molecule with only two atoms is inherently linear.
This is due to the electron pairs, both bonding and non-bonding (lone pairs), arranging themselves to minimize repulsion, making the angle between them 180°. Examples of molecules with a linear geometry include BeH2 and CO2. When only two electron groups are present, they align 180° apart, resulting in a linear molecular shape.