The complete question is shown in the image attached
Answer:
See explanation
Explanation:
In a molecule, the direction of the dipole moment also shows the direction of the shift in electron density. Let me give you an instance. In HCl, the dipole points towards the chlorine atom. This implies that the bond is polar and the chlorine atom accommodates the greater share of the electron density of the H-Cl bond. The negative partial charge rests on the more electronegative atom (chlorine in this case) while the partial positive charge rests on the more electropositive atom(hydrogen in this case). Recall that the difference in electron density between the two atoms creates this polarity.
Having said that much, let me come to the issue of electronegativity and bond polarity. The polarity of bonds depends on the electronegativity difference between atoms. I have just established that the H-Cl bond is polar owing to the difference in electronegativity between hydrogen and chlorine. If I replace the chlorine atom in the molecule with another hydrogen atom, the molecule is no longer polar because the difference in electronegativity of a H-H bond is zero.
Lastly, let me talk about electronegativity difference and bond character. The magnitude of electronegativity difference between atoms determines the bond character. If the electronegativity difference between bonding atoms is;
less than 0.4, the bond is a pure covalent bond
between 0.4 - 1.8, the bond is a polar covalent bond
greater than 1.8, the bond is a pure ionic bond
