Metallic solid consists of several metal atoms of the same kind bonded together closely. Due to their large size, metals easily lose their outermost valence electrons. The delocalized valence electron drifts and is now available for the other nuclei of metal atoms. Several delocalized electrons are comparable to a sea of electrons.
Once the atom loses its electrons, it becomes positively charged. It is still an atom and not an ion since the atom tries to maintain electrical neutrality by attracting neighboring electrons. The floating free electrons try and attach themselves electrostatically to the positive metal atoms. Again, they detach and reattach in a repeating sequence of events, and this type of metallic bonding is responsible for several unique characteristics of the metals.

This is additional content for the chapter Bonding in Atoms in CurlyArrows' Introduction to Organic Chemistry Course. Preview the Book.
Related Reading- Metallic Bond
