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
Metalloid Silicon is present in silatrane, a highly toxic rodenticide. Long-term inhalation of silica dust causes silicosis, a fatal disease of the lungs. Silicon is an essential trace element. Silicone gel can be applied to badly burned patients to reduce scarring. Salts of germanium are potentially harmful to humans and animals if ingested on a prolonged basis. There is interest in the pharmacological actions of germanium compounds but no licensed medicine as yet. Arsenic is notoriously poisonous and may also be an essential element in ultratrace amounts. During World War I, both sides used "arsenic-based sneezing and vomiting agents…to force enemy