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Phosphorus (P)

Phosphorus is a chemical element of the periodic table with chemical symbol P and atomic number 15 with an atomic weight of 30.9738 u and is classed as nonmetal and is part of group 15 (nitrogen group). Phosphorus is solid at room temperature.

Phosphorus in the periodic table

Atomic number15
Group15 (Nitrogen group)
AppearanceColourless, waxy white, yellow, scarlet, red, violet, black
Color Colorless
Number of protons15 p+
Number of neutrons16 n0
Number of electrons15 e-
From Wikipedia, the free encyclopediaPhosphorus is a chemical element with symbol P and atomic number 15. As an element, phosphorus exists in two major forms—white phosphorus and red phosphorus—but due to its high reactivity, phosphorus is never found as a free element on Earth. Instead phosphorus-containing minerals are almost always present in their maximally oxidised state, as inorganic phosphate rocks.

Physical properties

Phase at STPSolid
Density1.823 g/cm3
Atomic weight30.9738 u

Thermal properties

Melting point-
Boiling point-
Heat of vaporization12.4 kJ/mol

Atomic properties

Electronegativity (Pauling Scale)2.19
Electron affinity72.037 kJ/mol
Oxidation states−3, −2, −1, 0, +1, +2, +3, +4, +5
(a mildly acidic oxide)
Ionization energies
  1. 1011.8 kJ/mol
  2. 1907 kJ/mol
  3. 2914.1 kJ/mol
  4. 4963.6 kJ/mol
  5. 6273.9 kJ/mol
  6. 21267 kJ/mol
  7. 25431 kJ/mol
  8. 29872 kJ/mol
  9. 35905 kJ/mol
  10. 40950 kJ/mol
  11. 46261 kJ/mol
  12. 54110 kJ/mol
  13. 59024 kJ/mol
  14. 271791 kJ/mol
  15. 296195 kJ/mol

Electron configuration for phosphorus

Electron configuration
Shorthand configuration
[Ne] 3s2 3p3
Electron configuration
Full configuration
1s2 2s2 2p6 3s2 3p3
Electron configuration chart
Electrons per shell2, 8, 5
Valence electrons 5
Valency electrons 3,5
Bohr model
PhosphorusElectron shell for Phosphorus, created by Injosoft ABP
Figure: Shell diagram of Phosphorus (P) atom.
Orbital Diagram

The history of Phosphorus

Discovery and first isolationHennig Brand (1669)
Recognised as an element byAntoine Lavoisier (1777)
Discovery of phosphorus
The discovery of phosphorus, the first element to be discovered that was not known since ancient times, is credited to the German alchemist Hennig Brand in 1669, although others might have discovered phosphorus around the same time. Brand experimented with urine, which contains considerable quantities of dissolved phosphates from normal metabolism. Working in Hamburg, Brand attempted to create the fabled philosopher's stone through the distillation of some salts by evaporating urine, and in the process produced a white material that glowed in the dark and burned brilliantly. It was named phosphorus mirabilis ("miraculous bearer of light"). Phosphorus was the 13th element to be discovered. Because of its tendency to spontaneously combust when left alone in air, it is sometimes referred to as "the Devil's element".


List of unique identifiers for Phosphorus in various chemical registry databases
CAS Number7723-14-0
ChemSpider ID4575369
EC number231-768-7
PubChem CID Number5462309