Arsenic (As), a chemical element in the nitrogen group (Group 15 [Va] of the periodic table), existing in both gray and yellow crystalline forms. Arsenic was known in the form of certain of its compounds long before it was clearly recognized as a chemical element. In the 4th century BCE Aristotle wrote of a substance called sandarache, now believed to have been the mineral realgar, a sulfide of arsenic. Continue reading from Encyclopedia Britannica
A more dangerous form of arsenic, called white arsenic, has also been long known. This was the trioxide, As2O3, and was a by-product of copper refining. When this was mixed with olive oil and heated it yielded arsenic metal itself. The discovery of the element arsenic is attributed to Albertus Magnus in the 1200s. Continue reading from The Royal Society of Chemistry
From the time of the Roman Empire all the way to the Victorian era, arsenic was considered the "king of poisons" as well as the "poison of kings." Arsenic poisoning can cause all sorts of health problems. A large dose can cause immediate sickness and death, while long-term exposure is associated with higher rates of skin, bladder and lung cancers, as well as heart disease
Under standard atmospheric pressure, arsenic sublimes, or changes directly from the solid state to the gaseous state without becoming a liquid. However, it will turn into a liquid when put under high pressure. Arsenic is sometimes alloyed with lead to form a harder, more durable metal. Some areas of use include car batteries and bullets. Until recently, arsenic was commonly used in glassmaking. Continue reading from LiveScience