Iodide is a negatively charged ion of iodine, represented by the chemical symbol I-. It is commonly found in nature, particularly in seawater and certain minerals. Iodide plays a crucial role in human health, as it is essential for the production of thyroid hormones, which regulate metabolism and growth. In addition to its biological importance, iodide is used in various applications, including medical imaging and disinfectants. It can be found in iodized salt, which helps prevent iodine deficiency in populations. Overall, iodide is vital for both health and industry.