Es-252 is an isotope of the element Einsteinium, which is a synthetic element with the atomic number 99. It was first discovered in 1952 as a byproduct of nuclear reactions involving plutonium in atomic bomb tests. Es-252 has a half-life of approximately 471.7 days, making it relatively stable compared to other isotopes of Einsteinium. This isotope is primarily used in scientific research, particularly in the fields of nuclear chemistry and radiochemistry. Due to its radioactive properties, Es-252 can be utilized in various applications, including neutron sources and studies of heavy elements.