Assuming that "least nonmetallic" means the same as "most metallic", francium.
The element in Period 3 that has the greatest metallic character is magnesium. In periods, the metallic character decreases when atomic number increases.
It is the fourth least reactive element, followed by Mercury, Gold and Platinum.
Metallic bond, metallic positive grains surrounded by the electron cloud
No element contains any kind of bond except a metallic one. Ionic bonds can occur only between at least two different elements.
cadmium
The lowest atomic weight between iron and tin is that of silver.
zinc
Metallic
Assuming that "least nonmetallic" means the same as "most metallic", francium.
The element in Period 3 that has the greatest metallic character is magnesium. In periods, the metallic character decreases when atomic number increases.
It is the fourth least reactive element, followed by Mercury, Gold and Platinum.
Metallic bond, metallic positive grains surrounded by the electron cloud
No element contains any kind of bond except a metallic one. Ionic bonds can occur only between at least two different elements.
Refined and polished, it is indistinguishable from silver, at least upon casual inspection.
Bi, bismuth, is actually just an element. A compound is made up of at least two different elements bonded together.
Ionic compounds do not require the presence of a metal, for example ammonium chloride is ionic and does not contain a metallic element. What is true is that the majority of ionic compounds involve at least one metal.