57  Lanthanum

 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      

+--------------------+
| 57  _              |
|    | |    __ _     |
|    | |   / _` |    |
|    | |__| (_| |    |
|    |_____\__,_|    |
|                    |
|      Lanthanum     |
|     138.9055 u     |
+--------------------+

Electron Configuration: [Xe]6s2 5d1
Electronegativity:      1.1
Atomic Radius:          240 pm
Ionization Energy:      5.577 eV
Electron Affinity:      0.5 eV
Oxidation States:       3
Standard State:         Solid
Melting Point:          1191 K
Boiling Point:          3737 K
Density:                6.15 g/cm3
Family:                 Lanthanide
Year Discovered:        1839
Number of Neutrons:     82
Number of Protons:      57
Number of Electrons:    57
Number of Valence:      
Valency:                
Group:                  3
Period:                 6
Shell:                  f-shell
Specific Heat:          0.195 J/g K
Radioactive:            0
Occurrence:             Natural
Source:                 Dying low-mass stars
Source:                 Merging neutron stars