15  Phosphorus

 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      

+--------------------+
| 15     ____        |
|       |  _ \       |
|       | |_) |      |
|       |  __/       |
|       |_|          |
|                    |
|     Phosphorus     |
|    30.97376200 u   |
+--------------------+

Electron Configuration: [Ne]3s2 3p3
Electronegativity:      2.19
Atomic Radius:          180 pm
Ionization Energy:      10.487 eV
Electron Affinity:      0.746 eV
Oxidation States:       +5, +3, -3
Standard State:         Solid
Melting Point:          317.3 K
Boiling Point:          553.65 K
Density:                1.82 g/cm3
Family:                 Nonmetal
Year Discovered:        1669
Number of Neutrons:     16
Number of Protons:      15
Number of Electrons:    15
Number of Valence:      5
Valency:                3
Group:                  15
Period:                 3
Shell:                  p-shell
Specific Heat:          0.769 J/g K
Radioactive:            0
Occurrence:             Natural
Source:                 Dying high-mass stars