Metastable Black Arsenic Proven to Exist
Phosphorus and arsenic are on top of each other in one group of the periodic table, so they have many similar properties. In addition to tubular forms, phosphorus is found in white, red, black and purple structural forms. At room temperature, black phosphorus is the stable form; the others are metastable. According to textbooks, arsenic occurs in gray, yellow and black forms. However, the existence of black arsenic, which should be analogous to black phosphorus, has never been indisputably proven. In the journal Angewandte Chemie, researchers from Technische Universitaet Muenchen, Univ. of Regensburg and Lausitz Univ. of Applied Sciences have now demonstrated that black arsenic is metastable in its pure form, and that it has thus far only been obtained in a form stabilized by atoms of other elements.
Read more: http://www.laboratoryequipment.com/news-Black-Arsenic-is-Proven-to-Exist-Metastable-022212.aspx
