Noble metal are covered by carbon monoxide very quickly. Metallic elements, including metalloids (metals usually considered noble bolded, predictions for superheavy elements italicised): The columns "group" and "period" denote its position in the periodic table, hence electronic configuration. The simplified "reaction"s, listed in the next column, can also be read in detail from the Pourbaix diagrams of the considered element in water. Finally the column "potential" indicates the electric potential of the element measured against a Standard hydrogen electrode. All missing elements in this table are either not metals or have a negative standard potential. Arsenic, antimony and tellurium are considered to
Tellurium alpha decay. The atomic mass of tellurium (127.60 g·mol) exceeds that of iodine (126.90 g·mol), the next element in the periodic table. With an abundance in the Earth's crust comparable to that of platinum (about 1 µg/kg), tellurium is one of the rarest stable solid elements. In comparison, even the rarest of the stable lanthanides have crustal abundances of 500 µg/kg (see Abundance of the chemical elements). This rarity of tellurium in the Earth's crust is not a reflection of its cosmic abundance. Tellurium is more abundant than rubidium in the cosmos, though rubidium is 10,000 times more abundant in