Understanding basic chemical concepts, including bonding, polar and nonpolar molecules, and hydrogen bonds is difficult for many biology students, who often have minimal chemistry backgrounds. The concept of electronegativity is introduced at the beginning of the chemical foundations part of a biology course as a central integrative concept. By using the electronegativity concept and an associated line graph, students gain an understanding of why ionic and covalent bonds form and which atoms form them, why atoms form polar and nonpolar covalent bonds, and what chemical groups can form hydrogen bonds. Positive student reviews indicate that this is an effective method for introducing chemical principles.