Element #99

• A radioactive transuranic element produced by bombarding plutonium with neutrons
• 99, in chemistry
• Transuranic element
• Radioactive element beginning to escape in minutes, I suspect

WordNet Word definitions in WordNet
n. a radioactive transuranic element produced by bombarding plutonium with neutrons [syn: Es , E , atomic number 99 ]

Wikipedia Word definitions in Wikipedia
Einsteinium is a synthetic element with symbol Es and atomic number 99. It is the seventh transuranic element , and an actinide . Einsteinium was discovered as a component of the debris of the first hydrogen bomb explosion in 1952, and named after Albert ...

Wiktionary Word definitions in Wiktionary
n. A transuranic chemical element (''symbol'' Es) with atomic number 99.

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Es \Es\ n. the chemical symbol for einsteinium , a transuranic element with atomic number 99. The atomic weight of the longest-lived isotope, with a half-life of 276 days, is 254. The first isotope discovered, having atomic weight 253 and a half-life of ...

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
radioactive element, discovered in the debris of a 1952 U.S. nuclear test in the Pacific, named 1955 for physicist Albert Einstein (1879-1955).