What is Arsenic atom?

   

 Arsenic is a chemical element with the symbol As and atomic number 33.  Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal.  Arsenic is a metalloid.  It has various allotropes, but only the gray form, which has a metallic appearance is important to industry.  

     The primary use of arsenic is in alloys of lead(for example, in car batteries and ammunition).  Arsenic is a common n-type dopant in semiconductor electronic gallium arsenide is the second most commonly used semiconductor 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 with the increasing recognition of the toxicity of arsenic and its compounds.  

     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 other species.  A role in human metabolism is not known.  However, arsenic poisoning occurs in multicellular life if quantities are larger then needed.  Arsenic  contamination  of groundwater is a problem that affects millions of people across the  world .