PERIODIC ELEMENT
Pa (Protactinium)

 



Atomic number : 91
Atomic mass : 231.0359 g mol-1
Electronegativity according to Pauling : 1.5
Density : 15.37 g cm-3 at 20 °C
Melting point : 1600 °C
Boiling point : unknown
Vanderwaals radius : unknown
Ionic radius : unknown
Isotopes : 5
Electronic shell : [ Rn ] 5f2 6d1 7s2
Discovered by : K. Kajans and O.H. Gohring in 1913
 
Atomic Structure Uses(unknown)