Protactinium

=Protactinium=


 * Atomic Number:** 91


 * Proton:** 91 


 * Electrons:**  91


 * Neutrons:** 140


 * Average Atomic Mass:** 231.036 amu


 * Isotopes:** 231Pa


 * Discovery:** Protactinium was discovered by Otto Hahn, Lise Meitner, Frederick Soddy, John Cranston at 1913 in Germany, England.
 * Name: From the Greek word "protos"**  meaning "first" iodide PaI5 under vacuum.


 * Uses:**none 


 * Interesting Facts**: It is one of the rarest and most expensive naturally occurring elements.It is one of the rarest and most expensive naturally occurring elements.

media type="youtube" key="3nZB4u34q98" height="344" width="425"
 * Video:**


 * Sources**

[|金星（きんせい）by manimalmagic has fleas (don't touch)'s photostream]

 * [|protactiniumvideo]

[|protactinumisotopes]