Menu
Other Resources

Compare Phosphorus vs Arsenic

Comparing Phosphorus (P) and Arsenic (As). Atomic numbers 15 and 33 with atomic masses 30.974 u and 74.922 u, classified as nonmetal and metalloid. Below: a side-by-side comparison of their physical, atomic, electron-configuration and historical properties, including density, melting and boiling points, ionization energies, oxidation states and discovery history.

vs
P
Phosphorus
#15
As
Arsenic
#33

Periodic properties of the elements

PhosphorusArsenic
SymbolPAs
Atomic number1533
Group1515
Period34
Blockpp
Element categoryNonmetalMetalloid

Physical properties

PhosphorusArsenic
Phase at STPSolidSolid
Density1.823 g/cm35.727 g/cm3
Atomic weight30.9738 u74.9216 u
Melting point--
Boiling point--

Atomic properties

PhosphorusArsenic
Electronegativity (Pauling Scale)2.192.18
Electron affinity72.037 kJ/mol77.65 kJ/mol
Oxidation states−3, −2, −1, 0, +1, +2, +3, +4, +5
(a mildly acidic oxide)		−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
  1. 947 kJ/mol
  2. 1798 kJ/mol
  3. 2735 kJ/mol
  4. 4837 kJ/mol
  5. 6043 kJ/mol
  6. 12310 kJ/mol

Electron configuration

PhosphorusArsenic
Shorthand configuration[Ne] 3s2 3p3 [Ar] 3d10 4s2 4p3
Full configuration1s2 2s2 2p6 3s2 3p3 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p3
Electrons per shell2, 8, 52, 8, 18, 5

History

PhosphorusArsenic
DiscoveryHennig Brand (1669)Zosimos of Panopolis (300)
First isolationHennig Brand (1669)
Compare Phosphorus with
Compare Arsenic with