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Arsenic (33 As) has 32 known isotopes and at least 10 isomers. Only one of these isotopes, 75 As, is stable; as such, it is considered a monoisotopic element . The longest-lived radioisotope is 73 As with a half-life of 80 days.
In As 4 S 10, arsenic has a formal oxidation state of +2 in As 4 S 4 which features As-As bonds so that the total covalency of As is still 3. [38] Both orpiment and realgar, as well as As 4 S 3, have selenium analogs; the analogous As 2 Te 3 is known as the mineral kalgoorlieite, [39] and the anion As 2 Te − is known as a ligand in cobalt ...
Arsenic forms colorless, odorless, crystalline oxides As 2 O 3 ("white arsenic") and As 2 O 5 which are hygroscopic and readily soluble in water to form acidic solutions. Arsenic(V) acid is a weak acid and the salts are called arsenates , [ 5 ] the most common arsenic contamination of groundwater , and a problem that affects many people.
Arsenic typically occurs in the oxidation states (III) and (V), illustrated by the halides AsX 3 (X = F, Cl, Br, I) and AsF 5. Correspondingly, organoarsenic compounds are commonly found in these two oxidation states. [3] The hydroxyarsenic compounds are known: [3] arsonous acids (RAs(OH) 2), rare (arsenous acid (As(OH) 3) is well known)
Arsenic is a metalloid with an atomic number of 33, and its common oxidation states are +3 or +5, as arsenate(As III) and arsenite(As V). [12] Arsenic is primarily found as organic arsenic compounds, inorganic arsenic compounds, and arsine gas.
Upon sublimation at 616 °C, the gas phase arsenic molecules lose this packing arrangement and form small clusters of As 4, As 2, and As, though As 4 is by far the most abundant in this phase. [1] If these vapors are condensed swiftly onto a cold surface (<200 K), solid yellow arsenic (As 4 ) results due to the lack of energy required to form ...
As 2 O 3 + 6 Zn + 12 HNO 3 → 2 AsH 3 + 6 Zn(NO 3) 2 + 3 H 2 O. In 1787, German physician Johann Metzger (1739-1805) discovered that if arsenic trioxide were heated in the presence of carbon, the arsenic would sublime. [4] This is the reduction of As 2 O 3 by carbon: 2 As 2 O 3 + 3 C → 3 CO 2 + 4 As
In the 18th century it was found that combining arsenic trioxide (As 2 O 3) and four equivalents of potassium acetate (CH 3 CO 2 K) gives a product called "Cadet's fuming liquid" which contains cacodyl oxide, ((CH 3) 2 As) 2 O and cacodyl, ((CH 3) 2 As) 2. Early research into "cacodyls" was reported by Robert Bunsen at the University of Marburg ...