Question

Which is most likely the result of millions of metal atoms crowding together so that molecular orbitals become combined?
the loss of metallic properties
the formation of bands in a crystal
the loss of valence electrons to other atoms
the formation of localized valence electrons

Answer 1

the formation of bands in a crystal

When many atoms come together, their atomic/molecular orbitals overlap and split into a continuum of closely spaced energy levels, forming energy bands (conduction and valence bands) characteristic of solids. This also leads to delocalized (not localized) valence electrons and metallic behavior.