Einsteinium Group Number
Einsteinium is a synthetic chemical element with the symbol Es and atomic number 99. It belongs to the actinide series of elements and has an electron configuration of [Rn] 5f^11 7s^2. The group number of einsteinium is not well-defined since it is not a naturally occurring element and does not belong to any particular group in the periodic table. However, it is commonly classified as a transuranic element and is located in group 3 of the f-block elements. Einsteinium was first synthesized in 1952 by a team of scientists led by Albert Ghiorso at the University of California, Berkeley, and was named after the physicist Albert Einstein. Due to its rarity and high radioactivity, there are no known practical applications for einsteinium.