Search results
Results From The WOW.Com Content Network
Arsenic trioxide powder.. Compounds of arsenic resemble in some respects those of phosphorus which occupies the same group (column) of the periodic table.The most common oxidation states for arsenic are: −3 in the arsenides, which are alloy-like intermetallic compounds, +3 in the arsenites, and +5 in the arsenates and most organoarsenic compounds.
Gray, or metallic arsenic, pictured under an argon atmosphere. Gray arsenic, also called grey arsenic or metallic arsenic, is the most stable allotrope of the element at room temperature, and as such is its most common form. [1] This soft, brittle allotrope of arsenic has a steel gray, metallic color, and is a good conductor. [2]
Main page; Contents; Current events; Random article; About Wikipedia; Contact us; Pages for logged out editors learn more
Arsenic is used as the group 5 element in the III-V semiconductors gallium arsenide, indium arsenide, and aluminium arsenide. [41] The valence electron count of GaAs is the same as a pair of Si atoms, but the band structure is completely different which results in distinct bulk properties. [42]
The group 1 alkali metals and the group 2, alkaline earth metals, form arsenides with isolated arsenic atoms. They form upon heating arsenic powder with excess sodium gives sodium arsenide (Na 3 As). The structure of Na 3 As is complex with unusually short Na–Na distances of 328–330 pm which are shorter than in sodium metal.
Trimethylarsine (abbreviated TMA or TMAs) is the chemical compound with the formula (CH 3) 3 As, commonly abbreviated AsMe 3 or TMAs. This organic derivative of arsine has been used as a source of arsenic in microelectronics industry, [1] a building block to other organoarsenic compounds, and serves as a ligand in coordination chemistry.
In its standard state arsine is a colorless, denser-than-air gas that is slightly soluble in water (2% at 20 °C) [1] and in many organic solvents as well. [citation needed] Arsine itself is odorless, [5] but it oxidizes in air and this creates a slight garlic or fish-like scent when the compound is present above 0.5 ppm. [6]
The Marsh test treats the sample with sulfuric acid and arsenic-free zinc. Even if there are minute amounts of arsenic present, the zinc reduces the trivalent arsenic (As 3+). Here are the two half-reactions: Oxidation: Zn → Zn 2+ + 2 e − Reduction: As 2 O 3 + 12 e − + 6 H + → 2 As 3− + 3 H 2 O. Overall, we have this reaction: