61  Promethium

 H                                                  He
 Li Be                               B  C  N  O  F  Ne
 Na Mg                               Al Si P  S  Cl Ar
 K  Ca Sc Ti V  Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
 Rb Sr Y  Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I  Xe
 Cs Ba La Hf Ta W  Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
 Fr Ra Ac Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og
                                                      
       Ce Pr Nd[Pm]Sm Eu Gd Tb Dy Ho Er Tm Yb Lu      
       Th Pa U  Np Pu Am Cm Bk Cf Es Fm Md No Lr      

+--------------------+
| 61____             |
|  |  _ \ _ __ ___   |
|  | |_) | '_ ` _ \  |
|  |  __/| | | | | | |
|  |_|   |_| |_| |_| |
|                    |
|     Promethium     |
|     144.91276 u    |
+--------------------+

Electron Configuration: [Xe]6s2 4f5
Electronegativity:      
Atomic Radius:          236 pm
Ionization Energy:      5.55 eV
Electron Affinity:      
Oxidation States:       3
Standard State:         Solid
Melting Point:          1315 K
Boiling Point:          3273 K
Density:                7.26 g/cm3
Family:                 Lanthanide
Year Discovered:        1945
Number of Neutrons:     84
Number of Protons:      61
Number of Electrons:    61
Number of Valence:      
Valency:                
Group:                  
Period:                 6
Shell:                  f-shell
Specific Heat:          
Radioactive:            1
Occurrence:             Rare
Source:                 Radioactive decay