Protactinium
Pa
Protactinium
Rare Earth
Atomic number:
91
Atomic weight:
231.03588
Shells:
2,8,18,32,20,9,2
Orbitals:
[Rn] 5f2 6d1 7s2
Melting point:
1600°C
Boiling point:
--
Covalent radius:
--
Å
Atomic volume:
15.0
cm³/mol
Atomic radius:
--
Å
Ionic radius:
--
Å
Electronegativity:
1.5
Oxidation states:
(5),4
1st ionization pot.:
5.89
V
2nd ionization pot.:
--
V
3rd ionization pot.:
--
V
Specific heat:
0.12
J/gK
Heat of fusion:
12.30
kJ/mol
Heat of vapor.:
--
kJ/mol
Thermal conduct.:
0.47
W/cmK
Electrical conduct.:
0.0529
10^6/cm ohm
Density:
15.4
g/cm³
Valence:
4,5
