What is the electronegativity difference (delta EN) for polar covalent bonds?

Polar covalent bonds occur when there is a moderate difference in electronegativity between the two atoms involved in the bond. The electronegativity difference (delta EN) for polar covalent bonds typically falls within the range of 0.5 to 1.7. This range indicates that one atom attracts the shared electrons more strongly than the other, creating a dipole moment where one end of the bond becomes partially negative and the other partially positive.

This contrast in electronegativity is essential for understanding the nature of polar covalent bonds. When the difference falls below 0.5, the bond is generally considered nonpolar covalent, meaning that the electrons are shared more equally. On the other hand, a delta EN greater than 1.7 suggests that the bond has more ionic character, where one atom effectively transfers electrons rather than sharing them. Therefore, the correct range for polar covalent bonds is indeed 0.5 to 1.7, which highlights the nuances of bonding and electronegativity in molecular interactions.