Barium-137m is a radioactive isotope of barium, which is a chemical element with the symbol Ba. It is produced as a decay product of cesium-137, a byproduct of nuclear fission. Barium-137m has a half-life of about 2.55 minutes, meaning it takes this amount of time for half of a sample to decay into stable barium-137. This isotope is commonly used in medical applications, particularly in nuclear medicine for imaging and treatment purposes. Its short half-life allows for quick diagnostic procedures, minimizing radiation exposure to patients while providing valuable information for medical assessments.