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
Period 4 element can also be found in semiconductors. Germanium (Ge) is an element in period 4, between gallium and arsenic. Germanium, like silicon above it, is an important semiconductor and is commonly used in diodes and transistors, often in combination with arsenic. Germanium is fairly rare on Earth, leading to its comparatively late discovery. Germanium, in compounds, can sometimes irritate the eyes, skin, or lungs. Arsenic (As) is an element in period 4, between germanium and selenium. Arsenic, as mentioned above, is often used in semiconductors in alloys with germanium. Arsenic, in pure form and some alloys, is incredibly poisonous to all