How do metal atoms form metallic bonds?
Metals do not ever bond with other metals. Metals and nonmetals (or metalloids) bond together to form ionic compunds. They have charges and when being formed exchange electrons by the metal losing them and the nonmetal gaining it. Molecular compunds form between nonmetals and nonmetals (or between metalloids). Thay have oxidation states and when being formed share electrons to created double/triple/etc. bonds. However, metal atoms will never bond with other metal atoms.