| Symbol |
Pa |
|
| Atomic Number |
91 |
Relative Atomic Mass
12C = 12.0000 |
231.03588 |
Atomic Radius
pm |
161 |
First Ionisation Energy
kJ mol-1 |
568 |
| Electronegativity |
1.5 |
Density
kg m-3 |
15370 (est.) |
Molar Volume
cm3 |
15.0 |
Thermal Conductivity
W m-1 K-1 |
47 [300 K] (est.) |
Melting Point
K |
2113 |
Boiling Point
K |
c. 4300 |
| Number of Isotopes |
21 |
Ground State Electron
Configuration |
[Rn]5f26d17s2 |
| Term Symbol |
4K11/2 |
| Discovery |
234Pa was discovered by Kasimir Fajans and O.H. Goehring in 1913. 231Pa was discovered by L. Meitner, O. Hahn (Berlin Germany), K. Fajans (Karlsruhe, Germany), F. Soddy, J.A. Cranston and A. Fleck (Glasgow, Scotland) in 1917 |
| Name Derived From |
Greek protos meaning 'first' |
Name in Other
Languages |
 Croatian | Protaktinij |
 Danish | protactinium |
 Dutch | protactinium |
 Finnish | protaktinium |
 French | protactinium |
 German | Protactinium |
 Italian | protactinio |
 Norwegian | protactinium |
 Portuguese | protacnídio |
 Spanish | protactinio |
 Swedish | protaktinium |
| Peter van der Krogt's Element Multidict - element name translations in over 48 langauges |
