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Hydrogen Reference Libraries

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Astatine
2009-07-09 17:47:41

Astatine is a radioactive chemical element. The symbol for Astatine is At and its atomic number is 85. Astatine is the heaviest halogen discovered. It was first produced by Dale R. Corson, Kenneth Ross Mackenzie, and Emilio Segrè in 1940. Although astatine is produced by radioactive decay in nature, it is typically found only in miniscule amounts due to its short half-life (the time it takes...

Word of the Day
sudarium
  • A handkerchief.
  • Specifically— The legendary sweat-cloth; the handkerchief of St. Veronica, according to tradition miraculously impressed with the mask of Christ; also, the napkin about Christ's head (Johu xx. 7).
  • In general, any miraculous portrait of Christ.
The word 'sudarium' comes from a Latin word meaning 'a handkerchief'.