Final answer:
Double and triple bonds, due to their higher electron density, occupy more space around the central atom compared to single bonds, thus affecting the molecular geometry and resulting in smaller bond angles. Triple bonds are also shorter and stronger than double bonds, restricting rotation and contributing to linear molecular geometry.
Step-by-step explanation:
Double and triple bonds place greater electron density on one side of the central atom than do single bonds, therefore affecting the molecular geometry and potentially making other bond angles smaller. The reason is that these multiple bonds have a higher electron density and thus, occupy more space around the central atom compared to single bonds. This concept is illustrated when considering a molecule like CHâ‚‚O (formaldehyde), where the carbon and oxygen atoms form a double bond, influencing the shape and bond angles of the entire molecule.
Molecules with multiple bonds, like double or triple bonds, show changes in their physical properties too. A triple bond is shorter and stronger than a double bond between the same two atoms, and the same holds true for double versus single bonds. Consequently, triple bonds restrict rotational freedom around the bond axis, unlike single bonds, and provide the molecule with rigidity and linear geometry.