37  Rubidium

 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      

+--------------------+
| 37  ____  _        |
|    |  _ \| |__     |
|    | |_) | '_ \    |
|    |  _ <| |_) |   |
|    |_| \_\_.__/    |
|                    |
|      Rubidium      |
|      85.468 u      |
+--------------------+

Electron Configuration: [Kr]5s1
Electronegativity:      0.82
Atomic Radius:          303 pm
Ionization Energy:      4.177 eV
Electron Affinity:      0.468 eV
Oxidation States:       1
Standard State:         Solid
Melting Point:          312.46 K
Boiling Point:          961 K
Density:                1.53 g/cm3
Family:                 Alkali metal
Year Discovered:        1861
Number of Neutrons:     48
Number of Protons:      37
Number of Electrons:    37
Number of Valence:      1
Valency:                1
Group:                  1
Period:                 5
Shell:                  s-shell
Specific Heat:          0.363 J/g K
Radioactive:            0
Occurrence:             Natural
Source:                 Dying high-mass stars