Question

Metals can gain electrons or not

Answer 1

Metals tend to lose electrons to attain Noble Gas electron configuration. Groups 1 and 2 (the active metals) lose 1 and 2 valence electrons, respectively, because of their low Ionization energies. Non-metals are limited to the elements in the upper right hand corner of the Periodic Table.
Metals like to lose valence electrons to form cations to have a fully stable octet. They absorb energy (endothermic) to lose electrons. The electron affinity of metals is lower than that of nonmetals. Nonmetals like to gain electrons to form anions to have a fully stable octet.