Which of the following factors primarily determines the bond length between two atoms in a molecule?

• A. The sizes of the bonded atoms and the number of shared electron pairs
• B. The color of the atoms involved
• C. The pressure applied to the molecule during formation
• D. The temperature at which the molecule is formed

Answer: (A)

Verified step by step guidance

1. Understand that bond length is the average distance between the nuclei of two bonded atoms in a molecule.
2. Recognize that bond length depends mainly on two factors: the sizes (atomic radii) of the bonded atoms and the number of shared electron pairs (bond order).
3. Recall that larger atoms have longer bond lengths because their nuclei are farther apart, and more shared electron pairs (like double or triple bonds) pull atoms closer together, shortening the bond length.
4. Eliminate factors that do not primarily affect bond length, such as the color of atoms, pressure during formation, or temperature during formation, since these do not directly influence atomic sizes or bond order.
5. Conclude that the primary determinants of bond length are the sizes of the bonded atoms and the number of shared electron pairs between them.