Nonmetal as nonmetals. Among the reactive nonmetals, carbon, phosphorus, selenium, and iodine—which border the metalloids—show some metallic character, as does hydrogen. Among the noble gases, radon is the most metallic and begins to show some cationic behaviour, which is unusual for a nonmetal. The seven metalloids are boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te), and astatine (At). On a standard periodic table, they occupy a diagonal area in the p-block extending from boron at the upper left to astatine at lower right, along the dividing line between metals and nonmetals shown on some periodic tables. They
Post-transition metal one early use was in 1940 in a chemistry text. Alternate names for this group are "B-subgroup metals, other metals," and "p-block metals;" and at least eleven other labels. Usually included in this category are the group 13–15 metals in periods 4–6: gallium, indium and thallium; tin and lead; and bismuth. Other elements sometimes included are the group 11 metals copper, silver and gold (which are usually considered to be transition metals); the group 12 metals zinc, cadmium and mercury (which are otherwise considered to be transition metals); and aluminium, germanium, arsenic, selenium, antimony, tellurium, and polonium (of which germanium,