Arsenic

Arsenic is a chemical element with symbol As and atomic number 33. Arsenic occurs in many minerals, usually in conjunction with sulfur and metals, and also as a pure elemental crystal. Arsenic is a metalloid. It can exist in various allotropes, although only the gray form has important use in industry.

The main use of metallic arsenic is for strengthening alloys of copper and especially lead (for example, in car batteries). Arsenic is a common n-type dopant in semiconductor electronic devices, and the optoelectronic compound gallium arsenide is the most common semiconductor in use after doped silicon. Arsenic and its compounds, especially the trioxide, are used in the production of pesticides, treated wood products, herbicides, and insecticides. These applications are declining, however.

A few species of bacteria are able to use arsenic compounds as respiratory metabolites. Trace quantities of arsenic are an essential dietary element in rats, hamsters, goats, chickens, and presumably many other species, including humans. However, arsenic poisoning occurs in multicellular life if quantities are larger than needed. Arsenic contamination of groundwater is a problem that affects millions of people across the world.

Gertrude Yorkes

Gertrude Yorkes (self-referred to as Arsenic), is a fictional character in the Marvel Comics Runaways. She was created by author Brian K. Vaughan & artist Adrian Alphona, and debuted in Runaways vol. 1 #1 with most of the other main characters. Like every member of the original Runaways, she is the daughter of evil villains with special abilities; in Gert's case, time-travellers. Gertrude, often called "Gert" for short, is often regarded as the most "book-smart" of the Runaways yet also the most sarcastic and cynical. She has socialist leanings and is ethnically Jewish but spiritually agnostic. Gert is known for her sarcastic one-liners, a pair of glasses, and brown dyed purple hair. She stands at a rough height of 5'1" and weighs 125 lb (57 kg).

In 2008, Marvel.com named Gert's death as the sixth out of ten best deaths in Marvel Comics history.

Fictional character biography

The Pride

Isotopes of arsenic

Arsenic (As) has 33 known isotopes and at least 10 isomers. Only one of these isotopes, ⁷⁵As, is stable; as such, it is considered a monoisotopic element. The longest-lived radioisotope is ⁷³As has a half-life of 80 days. Arsenic has been proposed as a "salting" material for nuclear weapons (cobalt is another, better-known salting material). A jacket of ⁷⁵As, irradiated by the intense highenergy neutron flux from an exploding thermonuclear weapon, would transmute into the radioactive isotope ⁷⁶As with a half-life of 1.0778 days and produce approximately 1.13 MeV gamma radiation, significantly increasing the radioactivity of the weapon's fallout for several hours. Such a weapon is not known to have ever been built, tested, or used.

Relative atomic mass: 74.92160(2)

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