Question

Define the bond length.

Answer 1

Bond length is defined as the equilibrium distance between the nuclei of two bonded atoms in a molecule. Bond lengths are expressed in terms of Angstrom $\left({10}^{-10}m\right)$ or picometer $\left({10}^{–12}m\right)$ and are measured by spectroscopic X-ray diffractions and electron-diffraction techniques.

In an ionic compound, the bond length is the sum of the ionic radii of the constituting atoms (d = r+ + r–). In a covalent compound, it is the sum of their covalent radii $(d=r_A+r_B)$.