Arsenic essays

Arsenic essays Phosphorus (P), arsenic (As), antimony (Sb), and bismuth (Bi) form a group of four elements in Group 5A of the periodic table. They exhibit increasing metallic properties going down the group. Nitrogen (N), which heads the group, is a colorless, odorless, and tasteless gas. Phosphorus is a highly reactive nonmetal, arsenic and antimony are poisonous metalloids, and bismuth is a true metal. Because of the arrangement of the outer electrons in their atoms, each of these elements can form up to five chemical bonds with other elements or groups of elements. Arsenic has an atomic number 33, atomic mass is 74.9216, and it sublimes (passes directly into a vapor without melting) at 613Â ° C. The Earth's crust contains relatively little arsenic, only about 5.5 parts per million. Arsenic and some arsenic compounds have been known for a long time. Aristotle thought that arsenic was a kind of sulfur. The Latin word arsenicum means yellow orpiment (a pigment containing arsenic and sulfur). While knowledge of arsenic dates back to ancient Greece, it wasn't until the Middle Ages that its poisonous characteristics were described. It was identified by Albert Magnus about 1250, and he described the way to manufacture it. Since then the method has scarcely changed: the mineral arsenopyrite is heated and decomposes with the liberation of arsenic gas. The gas can be condensed on a cold surface. Metallic Arsenic was first produced in the 17th century by heating arsenic with potash and soap. Arsenic is very similar to antimony and bismuth. It exists in bright, metallic forms that are stable in air. It is found free in nature or in combination with other elements, usually sulfur. It is most often used to improve the strength and hardness of alloys, which are combinations of metals. Arsenic is a gray, shiny metalloid, which is a moderately good conductor of heat and electricity, but gray arsenic is brittle and breaks easily. This is the ordi...