Protactinium (Pa)
![](../Images/spacer.gif)
![](../Images/otherelements.gif)
![](../Images/spacer.gif)
![](../Images/neutralatom.gif)
![](../Images/singlyionized.gif)
![Homepage - Introduction Homepage - Introduction](../Images/mainPage.jpg)
![Finding list Finding list](../Images/findinglist.gif)
![Select element by name. Select element by name.](../Images/element_name_G.gif)
![Select element by atomic number. Select element by atomic number.](../Images/atomic_number_G.gif)
![Select element from periodic table Select element from periodic table](../Images/periodic_table_G.gif)
![](../Images/spacer.gif)
![Protactinium Atomic Data Protactinium Atomic Data](../Images/general_Y.gif)
![Protactinium Strong Lines Protactinium Strong Lines](../Images/strong_Y.gif)
![Protactinium Neutral Atom Persistent Lines Protactinium Neutral Atom Persistent Lines](../Images/persistent_Y.gif)
![Protactinium Neutral Atom Energy Levels Protactinium Neutral Atom Energy Levels](../Images/energy_Y.gif)
![Protactinium Singly Ionized Persistent Lines Protactinium Singly Ionized Persistent Lines](../Images/persistent_O.gif)
![Protactinium Singly Ionized Energy Levels Protactinium Singly Ionized Energy Levels](../Images/energy_O.gif)
References and Notes for Protactinium ( Pa )
BW92b J. Blaise and J.-F. Wyart, Energy Levels and Atomic Spectra of Actinides, International Tables of Selected Constants 20, Paris (1992). Also available at http//www.lac.u.psud.fr/Database/Contents.html.
G67 A. Giachetti, J. Opt. Soc. Am. 57, 728 (1967).
S74 J. Sugar, J. Chem. Phys. 60, 4103 (1974).