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Actinium
2009-07-09 17:04:18

Actinium is a radioactive chemical element. The symbol for Actinium is Ac and the atomic number is 89. Actinium was discovered in 1899 by French chemist André-Louis Debierne. It was the first non-primordial radioactive element to be isolated. Actinium is amongst a group of 15 similar elements within the periodic table that make up the actinoid series. This substance was also independently...

Word of the Day
caparison
  • A cloth or covering, more or less ornamented, laid over the saddle or furniture of a horse, especially of a sumpter-horse or horse of state.
  • Clothing, especially sumptuous clothing; equipment; outfit.
  • To cover with a caparison, as a horse.
  • To dress sumptuously; adorn with rich dress.
This word ultimately comes from the Medieval Latin 'cappa,' cloak.
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