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protoactinium

American  
[proh-toh-ak-tin-ee-uhm] / ˌproʊ toʊ ækˈtɪn i əm /

noun

Chemistry.
  1. protactinium.


protoactinium British  
/ ˌprəʊtəʊækˈtɪnɪəm /

noun

  1. the former name of protactinium

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Example Sentences

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Last month Dr. von Grosse asked to have the world supply of protoactinium back for a while so that he could make more photographs.

From Time Magazine Archive

When it slowly decays radioactively, it yields protoactinium 231 and thorium 230, both of which attach themselves to sediment particles and sink slowly to the bottom.

From Time Magazine Archive

There they in turn decay, but protoactinium 231 decays faster than thorium 230.

From Time Magazine Archive

Last week Dr. von Grosse created another stir by revealing that the world supply of protoactinium had unfortunately disappeared.

From Time Magazine Archive

Heavier than any other element except uranium, protoactinium is radioactive.

From Time Magazine Archive