Hydrogen fluoride features a polar bond due to the difference in electron density between its fluoride atom and its hydrogen atom. When an atom with greater electron density binds with one that features a lower electron density, the bond is considered a polar one, according to McGraw-Hill Education.
Polar molecules such as hydrogen fluoride bond based on the position and density of their electron fields. Scientists and chemistry students observe the orientation of this bond by placing the molecule in an electric field. When subjected to an electric field, the molecule's polarity causes the negatively charged atom to face the negative end of the field, while the positive atom faces the positive end.