Final answer:
The statement is true; atomic radii are used to estimate bond lengths in molecules by adding the radii of the individual atoms involved in a bond.
Step-by-step explanation:
Knowing atomic radii allows us to estimate bond lengths in molecules is true. Atomic radii can be determined by measuring the distance between the nuclei of two identical atoms bonded together and then dividing by two. This measure of the atomic radius, known as the covalent radius, is useful when predicting bond lengths between different atoms. For example, by adding up the atomic radii of two different elements, we can estimate the length of the bond that would form between them. A carbon-chlorine bond, predicted by adding the radii of carbon (77 pm) and chlorine (99 pm), equals 176 pm, which is close to the observed values in organochlorine compounds. Moreover, bond lengths are generally shorter for bonds that are stronger. For instance, triple bonds are shorter than double bonds between the same two atoms, and double bonds are shorter than single bonds. Bond distances are fundamental to understanding molecular structure and are important for explanations of the behavior of atoms or compounds.