Element: Phosphorus
General data
| Element name | Phosphorus |
|---|---|
| Chemical symbol | P |
| Atomic number Z | 15 |
| Year discovered | 1669 |
| Standard state (25°C) | Solid |
| Category | Nonmetal |
| Block | p |
| Atomic mass | 30.974 |
| CPK color | #FF8000 |
Physical properties
| Melting point | 317.3 K (44.2 °C) |
|---|---|
| Boiling point | 553.65 K (280.50 °C) |
| Density | 1.82 g/cm³ |
Energy properties
| First ionization energy | 10.487 eV |
|---|---|
| Electron affinity | 0.746 eV |
Atomic structure
| Protons | 15 (Atomic number) |
|---|---|
| Neutrons (P-31, most abundant isotope) | 16 |
| Electrons | 15 |
| Electron configuration | [Ne] 3s² 3p³ |
| Oxidation states | +5, +3, -3 |
| Electronegativity (Pauling) | 2.19 |
| Atomic radius (van der Waals) | 180 pm |
Ionization energies - NIST ASD (15 states)
| State | Charge | Ioniz. energy (eV) | Type |
|---|---|---|---|
| P I | 0+ | 10.486686 ± 0.000015 | measured |
| P II | 1+ | 19.76949 ± 0.00004 | semi-empirical |
| P III | 2+ | 30.20264 ± 0.00009 | measured |
| P IV | 3+ | 51.44387 ± 0.00012 | measured |
| P V | 4+ | 65.02511 ± 0.00012 | measured |
| P VI | 5+ | 220.43 ± 0.005 | semi-empirical |
| P VII | 6+ | 263.57 ± 0.06 | semi-empirical |
| P VIII | 7+ | 309.6 ± 0.1 | semi-empirical |
| P IX | 8+ | 372.31 ± 0.21 | semi-empirical |
| P X | 9+ | 424.4 ± 0.09 | semi-empirical |
| P XI | 10+ | 479.44 ± 0.05 | semi-empirical |
| P XII | 11+ | 560.62 ± 0.1 | semi-empirical |
| P XIII | 12+ | 611.741 ± 0.007 | calculated |
| P XIV | 13+ | 2816.90868 ± 0.00019 | calculated |
| P XV | 14+ | 3069.842145 ± 0.000014 | calculated |
Value type as given by NIST ASD: measured - from evaluated experimental data; calculated - from ab initio calculations (mostly highly ionised atoms that have not been measured; for the simplest ones, e.g. H I, the calculation is more accurate than measurement); semi-empirical - from interpolation, extrapolation or another semi-empirical method.
Photos
Isotopes (23)
| A | N | Half-life | Decay |
|---|---|---|---|
| P-25 | 10 | < 30 ns | p |
| P-26 | 11 | 43.6 ms | EC/β⁺ |
| P-27 | 12 | 260 ms | EC/β⁺ |
| P-28 | 13 | 270.3 ms | EC/β⁺ |
| P-29 | 14 | 4.102 s | EC/β⁺ |
| P-30 | 15 | 2.500 min | EC/β⁺ |
| P-31 | 16 | stable | - |
| P-32 | 17 | 14.267 d | β⁻ |
| P-33 | 18 | 25.35 d | β⁻ |
| P-34 | 19 | 12.43 s | β⁻ |
| P-35 | 20 | 47.3 s | β⁻ |
| P-36 | 21 | 5.6 s | β⁻ |
| P-37 | 22 | 2.31 s | β⁻ |
| P-38 | 23 | 640 ms | β⁻ |
| P-39 | 24 | 200 ms | β⁻ |
| P-40 | 25 | 150 ms | β⁻ |
| P-41 | 26 | 101 ms | β⁻ |
| P-42 | 27 | 48.5 ms | β⁻ |
| P-43 | 28 | 36.5 ms | β⁻ |
| P-44 | 29 | 18.2 ms | β⁻ |
| P-45 | 30 | 24 ms | β⁻ |
| P-46 | 31 | unknown | β⁻ |
| P-47 | 32 | unknown | β⁻ |
Data sources
- PubChem Periodic Table API - Retrieved on 29 June 2026 - licence: CC0
- IUPAC CIAAW - Abridged Standard Atomic Weights 2024 - Table version: 2024 - licence: Public domain
- NNDC Wallet Cards 2023 - Data as of 15 October 2024 - licence: Public domain
- NIST Atomic Spectra Database (ASD) - Retrieved on 29 June 2026 - licence: © U.S. Secretary of Commerce
- Images of Elements - Retrieved on 29 June 2026 - licence: CC BY 3.0