Q.Intra molecular hydrogen bonding is present in:

Metals show a distinctive property set — lustre, high density, high electrical and thermal conductivity, malleability, ductility, and high melting/boiling points — that neither ionic nor ordinary covalent bonding can explain. It is not ionic, since a metal's atoms are identical (no electronegativity difference to drive electron transfer); it is not ordinary covalent, since a metal atom lacks enough valence electrons to form individual shared-pair bonds with all 8 to 12 of its nearest neighbours in a close-packed crystal.

The Drude-Lorentz 'electron-sea' model pictures a metallic crystal as a regular lattice of positive metal ions immersed in a 'sea' of free, delocalised valence electrons (ionised from the metal atoms themselves and shared by ALL the ions in the crystal — hence metallic bonding is also called electronic bonding). This picture explains most metallic properties directly: high density and non-directional bonding follow from the electrostatic attraction between ions and the surrounding electron cloud (which envelops each ion equally in every direction); ductility follows from slip planes in the close-packed lattice, along which layers can slide without breaking the bonding; high electrical/thermal conductivity follows from the electrons' freedom of movement; metallic lustre follows from light reflecting off the mobile electron cloud; and high melting/boiling points follow from the strength of the overall bonding. …