Which of the following is not one of the three main kinds of bonds?

The three main types of chemical bonds typically considered in the context of chemistry are ionic, covalent, and metallic bonds. Ionic bonds occur when electrons are transferred from one atom to another, resulting in the formation of charged ions. Covalent bonds form when two atoms share electrons to achieve stability. Metallic bonds involve a 'sea of electrons' that are shared among a lattice of metal atoms, allowing them to conduct electricity and heat effectively.

Hydrogen bonds, while significant in biological systems and molecular interactions, are actually a type of intermolecular force rather than a primary bond type like the ionic, covalent, and metallic bonds. They arise from the attraction between a hydrogen atom (that is covalently bonded to an electronegative atom like oxygen or nitrogen) and another electronegative atom. Therefore, while hydrogen bonds are important in chemistry, particularly in the context of water and biological molecules such as DNA and proteins, they do not classify as one of the main types of bonds formed primarily between atoms.