15PPhosphorus30.973761998 u
Phosphorus (P)
Phosphorus is a nonmetal with atomic number 15, in period 3 and group 15 of the periodic table. Its atomic mass is 30.973761998 u and its electron configuration is [Ne] 3s² 3p³. Solid at 25 °C.
Key facts
| Atomic number | 15 |
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| Atomic mass | 30.973761998 u |
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| Category | Nonmetal |
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| Period | 3 |
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| Group | 15 |
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| Block | p |
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| Electron configuration | [Ne] 3s² 3p³ |
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| Electrons per shell | 2, 8, 5 |
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| Electronegativity (Pauling) | 2.19 |
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| Oxidation states | −3, −2, −1, +1, +2, +3, +4, +5common in bold |
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| State at 25 °C | Solid |
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| Melting point | 317.3 K44.15 °C |
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| Boiling point | 553.6 K280.45 °C |
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| Density | 1.823 g/cm³ |
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Atomic properties
| First ionization energy | 10.487 eV |
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| Electron affinity | 71 kJ/mol |
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| Atomic radius | 128 pm |
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| Covalent radius | 107 pm |
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| Van der Waals radius | 180 pm |
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| Common ions | P³⁻ |
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| Protons, neutrons, electrons | 15, 16, 15 |
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Physical and thermal properties
| Molar volume | 17.02 cm³/mol |
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| Heat of fusion | 0.64 kJ/mol |
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| Heat of vaporization | 12.4 kJ/mol |
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| Specific heat | 769.7 J/(kg·K) |
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| Thermal conductivity | 0.236 W/(m·K) |
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| Thermal expansion | --- |
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| Mohs hardness | --- |
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| Young’s modulus | --- |
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| Crystal structure | Simple triclinic |
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| Magnetic type | Diamagnetic |
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Identification and history
| CAS number | 7723-14-0 |
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| Latin name | Phosphorus |
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| Discovered by | Hennig Brand · 1669 |
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| Named by | --- |
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Natural isotopes
| Isotope | Mass (u) | Abundance |
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| 31P | 30.973762 | 100 % |
Data checked against PubChem (NIH), IUPAC, the NIST Atomic Spectra Database and the IAEA (NUBASE and AME), the same data you see in the app.
A dash (---) means there is no reliable published measurement. The app never makes one up.
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Periodic Table