| 31. | Protactinium exhibits two valence states; the + 5 is stable, and the + 4 state easily oxidizes to protactinium ( V ).
|
| 32. | Protactinium exhibits two valence states; the + 5 is stable, and the + 4 state easily oxidizes to protactinium ( V ).
|
| 33. | The thorium-233 beta decays to protactinium-233 and then to uranium-233, which in turn is used as fuel.
|
| 34. | Protactinium metal can be prepared by reduction of its fluoride with calcium fluoride, lithium or barium at a temperature of 1300 1400 �C.
|
| 35. | In the thorium cycle, thorium-232 breeds by converting first to protactinium-233, which then decays to uranium-233.
|
| 36. | The room temperature value for americium is lower than that of neptunium, plutonium and curium, but higher than for uranium, thorium and protactinium.
|
| 37. | The new element was called brevium due to the short half-life of the isotope specific studied, Protactinium-234 ( 234 Pa ).
|
| 38. | The complex chemical behavior of protactinium is a consequence of the start of the filling of the 5 " f " shell in this element.
|
| 39. | Thorium's melting point of 1750 �C is above both that of actinium ( 1227 �C ) and that of protactinium ( approximately 1560 �C ).
|
| 40. | Different isotopes of protactinium were identified in Germany in 1913 and in 1918, but the name " protactinium " was not given until 1948.
|
