Astatine is a very rare radioactive chemical element with the chemical
symbol At and the atomic number 85. It occurs on Earth as the decay
product of heavier elements. All its isotopes are short-lived, with
half-lives of 8.1 hours or less. The element has never been viewed
because a mass large enough to be seen would be immediately vaporized by
the heat of its radioactivity. The bulk properties of astatine are not
known with any certainty, but they have been predicted based on its
similarity to the lighter halogens directly above it in the periodic
table: fluorine, chlorine, bromine and especially iodine. It is likely
to appear dark or lustrous and may be a semiconductor or a metal.
Chemically, several anionic species of astatine are known and most of
its compounds resemble those of iodine. It also shows some metallic
behavior, and may be able to form a stable monatomic cation in aqueous
solution, unlike the lighter halogens.
Read more: <https://en.wikipedia.org/wiki/Astatine>
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Today's selected anniversaries:
1844:
Felix Mendelssohn completed the score of the Violin Concerto,
his final concerto.
<https://en.wikipedia.org/wiki/Violin_Concerto_%28Mendelssohn%29>
1963:
Malaysia was formed as an independent nation from the
Federation of Malaya, the Colony of Singapore, the Crown Colony of North
Borneo, and the Crown Colony of Sarawak.
<https://en.wikipedia.org/wiki/Malaysia>
1979:
Eight people escaped from East Germany to West Germany in a
home-made hot air balloon.
<https://en.wikipedia.org/wiki/East_German_balloon_escape>
1990:
Construction of the Northern Xinjiang railway (terminus
pictured) was completed between Ürümqi South and Alashankou, linking
the railway lines of China and Kazakhstan and adding a sizeable portion
to the Eurasian Land Bridge.
<https://en.wikipedia.org/wiki/Eurasian_Land_Bridge>
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Wiktionary's word of the day:
liken:
1. (transitive)
2. Followed by to or (archaic) unto: to regard or state that (someone or
something) is like another person or thing; to compare.
3. (also reflexive, rare) Chiefly followed by to: to make (oneself,
someone, or something) resemble another person or thing.
4. (rare) To represent or symbolize (something).
5. (intransitive, obsolete) Followed by to: to be like or resemble;
also, to become like.
<https://en.wiktionary.org/wiki/liken>
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Wikiquote quote of the day:
Heart of my heart, the world is young; Love lies hidden in every
rose!
--Alfred Noyes
<https://en.wikiquote.org/wiki/Alfred_Noyes>
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