At STP, which substance has metallic bonding?

(1) ammonium chloride (3) iodine

(2) barium oxide (4) silver

Silver has metallic bonding.

Silver is a very typical and main metal. The negatively charged electrons distribute themselves throughout the entire piece of metal and form non directional bonds between the positive silver ions, which is metallic bonding, and what silver contributes.

The answer is 4-silver because it is a metal ...