Einsteinium is a synthetic element with the symbol Es and atomic number 99. It was discovered in 1952 by a team of scientists who were studying the debris from a hydrogen bomb explosion. Einsteinium is part of the actinide series and is classified as a heavy metal. It is highly radioactive and has no significant commercial applications. Due to its radioactivity, einsteinium is primarily used for research purposes. It can be produced in minute quantities in nuclear reactors and is often studied to understand the properties of heavy elements. Its most stable isotope, Es-252, has a half-life of about 471.7 days.