The physical properties of metals such as malleability, ductility, electrical and thermal conductivity, luster e.t.c is controlled by metallic bonds.
Metallic bonds join atoms of metals and alloys together.
The formation of this bond type is favored by large atomic radius, low ionization energy and a large number of electrons in the valence shell.
Metallic bond is actually an attraction between the positive nuclei of all closely packed atoms in the lattice and the electron cloud jointly formed by all atoms losing their outermost shell electrons.