Which of the following best characterizes hydrogen bonds?

Hydrogen bonds are indeed best characterized as weak attractions that occur between polar molecules. This type of bond specifically arises when a hydrogen atom, which is covalently bonded to an electronegative atom (like oxygen or nitrogen), experiences an attraction to another electronegative atom in a nearby polar molecule. The polar nature of the molecules involved is crucial since the unequal sharing of electrons creates partial positive and negative charges, allowing for these weak intermolecular attractions.

This definition highlights the significance of polarity in the formation of hydrogen bonds, distinguishing it from covalent bonds, which involve the sharing of electrons rather than mere electrostatic attraction. The strength of hydrogen bonds, while notable in their biological and chemical impacts, is considerably weaker than covalent bonds.