NaI, or sodium iodide, is a chemical compound made up of sodium and iodine. It appears as a white, crystalline solid and is commonly used in various applications, including medical imaging and radiation detection. In its pure form, NaI is soluble in water and can form a solution that is useful in different scientific and industrial processes. In the field of nuclear medicine, NaI is often used in thyroid scans to help visualize the thyroid gland. It can also be employed in scintillation detectors, which are devices that detect and measure ionizing radiation. These properties make NaI an important compound in both healthcare and research.