Element Name: Einsteinium
Symbol: Es
Atomic Number: 99
Atomic Weight: 252 (this element has no stable isotopes; this is the mass number of the isotope with the longest half-life)
Element Category: Actinoid
General Description:
The seventh transuranic element, einsteinium is a soft, silvery, paramagnetic metal. It is the heaviest element to have been observed in macroscopic quantities in its pure form.
Einsteinium was discovered in the debris of the first hydrogen bomb explosion in 1952, and named after Albert Einstein. Its most common isotope einsteinium-253 is produced in a few dedicated high-power nuclear reactors with a total yield on the order of one milligram per year. Only a small amount of einsteinium can be produced at a single time, and given its short half-life, there are currently almost no practical applications for it outside of basic scientific research. In particular, einsteinium was used to synthesize, for the first time, 17 atoms of the new element mendelevium in 1955.
Effects on Human Body:
Like all synthetic transuranic elements, isotopes of einsteinium are extremely radioactive and are considered highly dangerous to health on ingestion.
Harrison JD. The gastrointestinal absorption of the actinide elements. Sci Total Environ. 1991 Mar;100 Spec No:43-60.