Einsteinium

Einsteinium is a chemical element with the atomic number 99. It is a synthetic element, so all isotopes are radioactive.

Einsteinium is the 7th element in the actinide series. The most stable isotope of Einsteinium has 99 protons and electrons and 153 neutrons. There are 19 different (radioactive) isotopes. Einsteinium is named after Albert Einstein. It was found for the first time in 1952 by Albert Ghiorso and his team of scientists in the debris of the first hydrogen bomb explosion, and identified as an element at the University of California, Berkeley.