Period 6 element years and is used in medical applications, industrial gauges, and hydrology. Although the element is only mildly toxic, it is a hazardous material as a metal and its radioisotopes present a high health risk in case of radioactivity releases. Barium is a chemical element with the symbol Ba and atomic number 56. It is the fifth element in Group 2, a soft silvery metallic alkaline earth metal. Barium is never found in nature in its pure form due to its reactivity with air. Its oxide is historically known as baryta but it reacts with water and carbon dioxide and is
Crystallographic defects in diamond measure the defect concentrations in diamond. In synthetic diamond grown by the high-pressure high-temperature synthesis or chemical vapor deposition, defects with symmetry lower than tetrahedral align to the direction of the growth. Such alignment has also been observed in gallium arsenide and thus is not unique to diamond. Various elemental analyses of diamond reveal a wide range of impurities. They mostly originate, however, from inclusions of foreign materials in diamond, which could be nanometer-small and invisible in an optical microscope. Also, virtually any element can be hammered into diamond by ion implantation. More essential are elements which can be introduced