Help in question 4.10
Bond length is defined as the equilibrium distance between the nuclei of two bonded atoms in a molecule.
Bondlengths are expressed in terms of Angstrom (10–10 m)or picometer
(10–12m) and are measured by spectroscopic X-ray diffractions and electron-diffraction techniques.
In anionic 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= rA + rB).