In molecules containing N-H, O-H or F-H bonds, the large difference in electronegativity between the H atom and the N, O or F atom leads to a highly polar covalent bond (i.e., a bond dipole). The electronegativities are listed below.
Also to know is, what is the polar covalent bond?
In a polar covalent bond, the electrons shared by the atoms spend a greater amount of time, on the average, closer to the Oxygen nucleus than the Hydrogen nucleus. This is because of the geometry of the molecule and the great electronegativity difference between the Hydrogen atom and the Oxygen atom.
How do we know if a bond is polar or nonpolar?
The greater the electronegativity difference, the more ionic the bond is. Bonds that are partly ionic are called polar covalent bonds. Nonpolar covalent bonds, with equal sharing of the bond electrons, arise when the electronegativities of the two atoms are equal.