Einsteinium is the 99th element of the periodic table. It is an actinide, and it is named after Albert Einstein.
Discovery
Einsteinium was first made during a hydrogen bomb test, in 1952. On filter papers on airplanes that flew through the debris cloud, and on coral debris blasted out by the explosion, about 200 atoms of einsteinium were detected. The process to make the einsteinium was as follows: A Uranium-238 atom would absorb 7 more neutrons, and beta-decay 7 times to create einsteinium-253.
Behavior
Einsteinium is a very radioactive element, and the heaviest that can be seen with the naked eye. The radiation is so intense that 300 micrograms would glow in the dark, like in the picture at right. The longest half-life of einsteinium is 472 days, and the element is so potentially dangerous that the labs that are allowed to create it can only create 5 milligrams maximum, half as much as a grain of sand. This helps picture how radioactive einsteinium is, because as much as half a grain of sand can create that bright glow seen in the picture.