The element with the strongest metallic properties in the world is francium, an artificial radioactive element. After francium, the next most metallic element is cesium.
When studying the periodic table, metallic characteristics increase through groups from right to left and through periods from top to bottom. Francium is also the most unstable element of the first 101 elements. Francium was discovered in 1939 by Marguerite Perey of the Curie Institute in Paris, France. The discovery of francium completed mankind's discoveries of elements that came naturally from the Earth. All elements discovered since then have been discovered when the element has been produced in the laboratory.