Hydrogen Bonds

A hydrogen atom (H) that is covalently attached to a more electronegative "donor" atom or group (Dn) and another electronegative atom containing a single pair of electrons—the hydrogen bond acceptor—are attracted to one another by an electrostatic force (Ac). The second-row elements nitrogen (N), oxygen (O), and fluorine (F) are used as donors and acceptors the most frequently (F). Intermolecular (between different molecules) or intramolecular hydrogen bonds are two different types of hydrogen bonding (occurring among parts of the same molecule). A hydrogen bond's energy can range from 1 to 40 kcal/mol and is influenced by its shape, surroundings, and the characteristics of the particular donor and acceptor atoms. They are therefore not totally covalent but are a little stronger than a van der Waals connection.