The valence electrons are easily dislodged from all of the atoms in the sample, and behave as a "sea of fluid electrons" surrounding positively charged metal cores.
Most metals are solids at room temperature, and they exist as highly-ordered 3-dimensional arrangements of vast numbers of atoms (i.e., as metallic crystals). The strength of metallic bonding varies significantly between different metal elements, and therefore melting points and mechanical strength also vary. Since the valence electrons are held loosely in all metallic solids, they are good conductors of electricity and heat, and they can be bent or shaped without breaking.
