Group 12 element ancient times as well as in alloys such as brass that have been found to be over 2000 years old. Zinc was distinctly recognized as a metal under the designation of "Fasada" in the medical Lexicon ascribed to the Hindu king Madanapala (of Taka dynasty) and written about the year 1374. The metal was also of use to alchemists. The name of the metal was first documented in the 16th century, and is probably derived from the German for the needle-like appearance of metallic crystals. The isolation of metallic zinc in the West may have been achieved independently by several
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