IMPORTANT POINTS FOR MCQS

BOND LENGTH

            The internuclear distance at which energy of the two bonded atoms is minimum, called

            equilibrium bond distance or bond length.OR

¥          The distance between the nuclei of two covalently bonded atoms is called bond length.

¥          It is measured in nano meter (nm) pico meter (pm) or angstrom (A⁰)

¥          Bond length decrease with increase in polarity.

¥          Triple covalent bond length is shorter than double which is shorter than single covalent         bond.

            C ≡ C is 120pm, C═ C is 134 pm and C ─ C is 154 pm

¥          Bond also depends on the size of the bonded atoms. H ─ H is shorter than Cl ─ Cl

¥          Stronger the bond shorter will be the bond length.

            Point to be noted.

            ►        Ionic character shortens the bond length.

            ►        Greater the electronegativity difference, shorter the bond length.

            ►        along group bond length increases.

                        B ― F bond length is 130 pm and that of B ― Cl is 175 pm

            ►        along period bond length decreases.