Einsteinium

Einsteinium was discovered in December 1952 by Albert Ghiorso and co-workers at the University of California, Berkeley, in collaboration with Argonne and Los Alamos national laboratories. The element was discovered in the fallout (or debris) from a thermonuclear device, which was exploded in the South Pacific. Because plutonium-244 was discovered on filter papers from a plane flown through the fallout, other filter papers were examined. Larger amounts of radioactive material were later isolated from the coral debris of an atoll.

The researchers were puzzled by the multiple neutron absorptions found when such a process was supposed to be extremely rare. Einsteinium, along with other actinide elements, was recovered. Its discovery was kept secret until 1955 because of the secrecy surrounding the nuclear test. It was named Einsteinium in honor of Albert Einstein.

Einsteinium is a soft, silvery, weakly magnetic, radioactive metal. It is among the heaviest elements that can be used in bulk studies.

Einsteinium has no commercial uses. It is used for basic scientific research in radiation damage, targeted radiation medical treatments, and accelerated aging.

Very few compounds are known, but include halogens (known as halides), oxygen (known as oxides), and hydrogen (known as hydrides).

Einsteinium is believed to have a face-centered cubic crystal symmetry. There is a report of a room-temperature hexagonal crystal, which converts to the face-centered cubic on heating.

Einsteinium has 19 known isotopes with mass number from 240 to 257. All of the isotopes are radioactive. The most stable isotope is einsteinium-252, with a half-life of 471.7 days. The next most stable isotopes are einsteinium-254 (half-life 275.7 days), einsteinium-255 (39.8 days), and einsteinium-253 (20.47 days). The remaining isotopes have half-lives shorter than 40 hours, with most being shorter than 30 minutes.

Einsteinium does not exist in nature. It is only produced in small amounts in nuclear reactors, scientific laboratories, or nuclear weapons tests.