Arsenic
Number of Electrons, Protons, Neutrons, Symbol and Name
Name: Arsenic
Symbol: As
Number of Protons: 33
Number of Electrons: 33
Number of Neutrons: 42
Melting Point: 817.0 ðC (1090.15 ðK, 1502.6 ðF)
Boiling Point: 613.0 ðC (886.15 ðK, 1135.4 ðF)
History
Arsenic: From the Latin word arsenicum, the Greek word arsenikon and the Arabic word Az-zernikh. Arsenic is pronounced AR-s'n-ik. Although the early Chinese, Greek mined arsenic compounds and Egyptian civilizations, it is believed that Albertus Magnus, a German alchemist, first identified arsenic itself.
Properties
Melting Point: 1090 K (1502.6ðF)
Boiling Point: 887 K (1137.2ðF)
Density: 5.776 grams per cubic centimeter
Phase at Room Temperature: Solid
Estimated Crustal Abundance: 1.8 milligrams per kilogram
Estimated Oceanic Abundance: 3.7-3 milligrams per liter
Number of Stable Isotopes: 1
Electron Shell Configuration: 1s2
2s2 2p6
3s2 3p6 3d10
4s2 4p3
Elemental arsenic occurs in two solid modifications: yellow, and grey or metallic, with specific gravities of 1.97,
and 5.73, respectively. The element is a steel Grey, very brittle, crystalline, semimetallic (metalloid) solid. It tarnishes in air, and when heated rapidly oxidizes to arsenous oxide which has a garlic odour.
Arsenic and its compounds are poisonous. Upon heating arsenic and some minerals containing arsenic, it sublimes (transfers from the solid to the gaseous state, without passing through the liquid state).
Chemical properties
Synonyms for arsenic are arsenic-75, metallic arsenic, arsenic black, arsenicals, and colloidal arsenic. The inorganic arsenic compounds are solids at normal temperatures and are not likely to volatilize. In water, they range from quite soluble (sodium arsenite and arsenic acid) too practically insoluble (arsenic trisulfide).
Some organic arsenic compounds are gases or low-boiling liquids at normal temperatures. Poisonous gas is produced by arsenic in a fire. Arsenic near acid or acid mist can release a very deadly gas, arsine. Twenty-one arsenic...