Barium

Barium is a soft, heavy, silver-colored metal element. This element does not have very many uses outside of the laboratory, but it combines easily with other chemicals to form compounds used for important industrial uses. For example, Barium carbonate is used in the manufacture of ceramics and special glass, and also to purify certain chemical solutions. It is also an ingredient in clay slurries, also known as water muds, used in drilling oil wells. Barium titanate is used in sonar detectors and other electrical equipment. At low doses, barium acts as a muscle stimulant and at higher doses affects the nervous system eventually leading to paralysis. Acute and subchronic oral doses of barium cause vomiting and diarrhea, followed by decreased heart rate and elevated blood pressure. Higher doses result in cardiac irregularities, weakness, tremors, anxiety, and dyspnea. A drop in serum potassium may account for some of the symptoms. Death can occur from cardiac and respiratory failure. Acute doses around 0.8 grams can be fatal to humans. Barium nitrate makes signal flares burn with a green flame. Barium ferrite is used to make magnets. Barium sulfate is an extremely insoluble barium compound that is not poisonous. Doctors use it in X-ray examinations of a patient's digestive system. The barium sulfate absorbs X rays to show an outline of the intestines on the developed film. A barium enema is performed to examine the walls of the colon. During the procedure, a well lubricated enema tube is inserted gently into the rectum. The barium is then allowed to flow into the colon. The flow of the barium is monitored by the health care provider on an X-ray fluoroscope screen. The test is used to detect colon cancer. The barium enema may also be used to diagnose and evaluate the extent of inflammatory bowel diseases. Barium sulfate and zinc sulfide form lithopone, a white coloring matter for paint. Barium is never found in a pure state because it combines so easily with other elements. Pure barium is obtained by passing an electric current through a fused barium compound, such as barium chloride. A piece of barium metal quickly reacts with oxygen and water vapor in the air to form barium oxide. It must be stored under kerosene to keep it pure. Barium is found most often as barium sulfate in the mineral barite. The chemical symbol for barium is Ba. Barium's atomic number is 56. Its relative atomic mass is 137.327. An element's relative atomic mass equals