Читать книгу Solid State Physics - Philip Hofmann - Страница 41

Hydrogen atoms possess only one electron and can form only one covalent bond. If this bond is formed with a very electronegative atom (like F or O), the electron is mostly located close to that atom and the hydrogen nucleus represents more or less an isolated positive (partial) charge. This can lead to a considerable charge density because of its small size, and it can therefore attract negative (partial) charges in other molecules to form an electrostatic bond. This type of bonding is called hydrogen bonding. It is usually quite weak, but in some cases, the cohesive energy can be up to several hundred meV per atom. It is responsible for the intermolecular attraction in (liquid and solid) water and for the bonding of the double helix strands in DNA.