Element 56 in our International Year of the Periodic Table series is barium. Barium is found in green fireworks, used in X-ray imaging, and also in drilling fluids.
Despite the toxicity of its compounds, barium sulfate is a compound given to patients as a ‘barium meal’ to allow X-ray imaging of the digestive system. This is possible because of the low solubility of barium sulfate – this stops the patient absorbing harmful amounts of barium as it passes through their body.
Barium sulfate is also used in a range of other applications. These include drilling fluids, white pigments in paints, and as a paper whitener.
Remember, you can keep track of all of the previous entries in this series on the site here, or on the Royal Society of Chemistry’s dedicated page.