93  Neptunium

 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      

+--------------------+
| 93  _   _          |
|    | \ | |_ __     |
|    |  \| | '_ \    |
|    | |\  | |_) |   |
|    |_| \_| .__/    |
|          |_|       |
|      Neptunium     |
|    237.048172 u    |
+--------------------+

Electron Configuration: [Rn]7s2 5f4 6d1
Electronegativity:      1.36
Atomic Radius:          221 pm
Ionization Energy:      6.266 eV
Electron Affinity:      
Oxidation States:       +6, +5, +4, +3
Standard State:         Solid
Melting Point:          917 K
Boiling Point:          4175 K
Density:                20.25 g/cm3
Family:                 Actinide
Year Discovered:        1940
Number of Neutrons:     144
Number of Protons:      93
Number of Electrons:    93
Number of Valence:      
Valency:                
Group:                  
Period:                 7
Shell:                  f-shell
Specific Heat:          
Radioactive:            1
Occurrence:             Rare
Source:                 Radioactive decay