，主要介绍元素砷
Arsenic (As), an element of the nitrogen group, is widely used in industrial applications, primarily in alloys, semiconductors and chemicals. It is also an important component of many biological pathways and is widely used in pharmaceuticals as well. Arsenic is a toxic element, especially in its inorganic forms, and exposure should always be minimized.
Arsenic has been found in nature since ancient times, and its name comes from the Latin words ars niger, which translates to black stone. Natural sources of arsenic include ground and surface water, the air, and soil. Indoor air has higher arsenic levels due to out-gasing from building materials and various other sources. In addition it is found in certain crops, and can be found in food and beverages that come in contact with arsenic-containing soil or drinking water.
Arsenic is naturally present in all rocks and soils, but is particularly abundant in sedimentary rocks such as shale. It is most commonly mined from arsenic-rich ores, such as arsenopyrite and realgar. Arsenic compounds can also be extracted from other sources, such as the processing of gold, copper and lead.
Arsenic compounds are widely used in industry, especially for adding strength, corrosion resistance and hardness to metals and alloys. Many semiconductor materials also contain arsenic, such as gallium arsenide and indium gallium arsenide. Arsenic is also used in many industrial chemicals and catalysts.
Several arsenic compounds are used in the medical field as well, such as the drugs melarsoprol and arsphenamine. Arsphenamine is used in the treatment of syphilis, while melarsoprol is used in the treatment of African sleeping sickness. Other medicinal uses of arsenic include the treatment of certain types of cancer and leukemia.
The toxicity of arsenic compounds is well known, and exposure should be minimized. Inhaling or consuming arsenic can cause major damage to the body, including anemia, cancer, and skin and respiratory irritation. In some cases, long-term exposure can lead to liver, kidney, and neurological problems as well.
Although arsenic is a naturally occurring element, it can also be produced in the laboratory. Arsenic can be produced via different synthetic pathways, such as the reaction of carbon and oxygen with arsenic trioxide. Arsenic can also be extracted from other common compounds such as water and soil.
With its wide range of uses, from industrial to medicinal, arsenic is an important element in modern society. As a toxin, though, exposure should always be minimized. Arsenic is found in nature and can be produced synthetically, and its compounds are used all over the world for various applications.
