Metallic bonds joins 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.
This bond type 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.
Some of the physical properties of metals such as malleability, ductility, electrical and thermal conductivity, luster, high melting point e.t.c stems from this.
