Final answer:
In molecules, triple bonds are shorter than double bonds, which are shorter than single bonds. Bond strength decreases down a group and hydrogen bonds are weaker and longer. Ozone has equivalent O-O bonds, while characteristic bond lengths and strengths vary by type and involved atoms in organic molecules.
Step-by-step explanation:
When comparing bond lengths of indicated bonds in molecules, a key factor to consider is the bond order, which is the number of shared electron pairs between two atoms. The general rule is that as bond order increases (e.g., from single to double to triple bonds), the bond strength increases and consequently the bond length decreases. Therefore, a triple bond is stronger and shorter than a double bond, and a double bond is stronger and shorter than a single bond between the same two atoms.
Additionally, bond strength tends to decrease as you move down a group of atoms in the periodic table. For example, the C-F bond is stronger than C-Cl, which in turn is stronger than C-Br. Furthermore, comparing hydrogen bonds to covalent bonds, hydrogen bonds are significantly weaker and longer; for instance, a hydrogen bond is around 23 kJ mol-1 compared to the much stronger covalent O-H bond at 492 kJ mol-1.
Specific examples like the ozone molecule (O3) show that the O-O bond length in such a molecule is identical and falls between what is typically expected of a single and a double bond. This is due to resonance or delocalization of electrons in the molecule leading to equivalent bond lengths. In organic molecules, bond lengths and strengths have characteristic values which differ based on the type of bond and the atoms involved, e.g., C-C single bonds are about 1.5 Å and C=C double bonds about 1.3 Å