Hydrogen bonding is most often seen see concept 2.3 (page 38) view available hint(s) hydrogen bonding is most often seen see concept 2.3 (page 38) when multiple carbon atoms are present when the bonds within the molecule are nonpolar covalent bonds in molecules whose three-dimensional shape is tetrahedral if the molecule consists of three or fewer atoms when hydrogen is covalently bonded to an electronegative atom

Answer;

When hydrogen is covalently bonded to an electronegative atom

Explanation;Hydrogen bonding is a special type of dipole-dipole attraction between molecules. It results from the attractive force between a hydrogen atom covalently bonded to a very electronegative atom such as a N, O, or F atom.Highly electronegative atoms attract shared electrons more strongly than hydrogen does, resulting in a slight positive charge on the hydrogen atom. The slightly positive hydrogen atom is then attracted to another electronegative atom, forming a hydrogen bond.