31  Gallium

 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      

+--------------------+
| 31   ____          |
|     / ___| __ _    |
|    | |  _ / _` |   |
|    | |_| | (_| |   |
|     \____|\__,_|   |
|                    |
|       Gallium      |
|      69.723 u      |
+--------------------+

Electron Configuration: [Ar]4s2 3d10 4p1
Electronegativity:      1.81
Atomic Radius:          187 pm
Ionization Energy:      5.999 eV
Electron Affinity:      0.3 eV
Oxidation States:       3
Standard State:         Solid
Melting Point:          302.91 K
Boiling Point:          2477 K
Density:                5.91 g/cm3
Family:                 Post-transition metal
Year Discovered:        1875
Number of Neutrons:     39
Number of Protons:      31
Number of Electrons:    31
Number of Valence:      3
Valency:                3
Group:                  13
Period:                 4
Shell:                  p-shell
Specific Heat:          0.371 J/g K
Radioactive:            0
Occurrence:             Natural
Source:                 Dying high-mass stars