Element identity
Atomic number, symbol, relative atomic mass display and periodic position are established reference data.
Atomic / electronic model
Ground-state electron configuration and atomic reference values are compiled/evaluated data; orbital graphics are teaching probability models, not photographs.
Material / molecular structure
The displayed ordinary structure is based on established material or molecular science; simplified viewers are labelled as teaching schematics where exact crystallographic coordinates are not rendered.
Temperature / phase path
Transition values are reference/evaluated values for the stated teaching path; pressure, purity and allotropy can matter.
Geography
Real pins use reviewed place/dataset context. Conceptual layers are used when country pins would imply false occurrence, unsafe inventory or an incomplete global distribution.
The lens describes evidence status, not confidence theatre. “Unknown” is kept unknown, and teaching schematics are not presented as direct measurements.
Phosphorus (P)
Phosphorus is element 15, a Group 15 nonmetal with five valence electrons and radically different allotropes. White P₄, red phosphorus and layered black phosphorus show how bonding and structure can transform the behavior of the same element.
Phosphorus atomic number, mass, electron configuration and key properties
Phosphorus: quick answers
How many protons, neutrons and electrons does phosphorus have?
Phosphorus’ atomic number is 15, so every phosphorus atom has 15 protons, and a neutral atom also has 15 electrons. Its most common natural isotope, phosphorus-31, has 16 neutrons (other isotopes have different neutron counts).
What is the symbol for phosphorus?
The chemical symbol for phosphorus is P.
Is phosphorus a solid, liquid or gas at room temperature?
Phosphorus is a solid at room temperature (about 25 °C).
What family (group) is phosphorus in?
Phosphorus is a nonmetal, in group 15, period 3 of the periodic table.
How many valence electrons does phosphorus have?
Phosphorus has 5 valence electrons, the electrons in its outer shell, which matches its position in group 15.
What is the electron configuration of phosphorus?
The ground-state electron configuration of phosphorus is [Ne] 3s² 3p³.
From atomic number to chemistry
Read these as a chain of causes, not as isolated facts. Each step links to the concept hub if you want the underlying idea explained.
Fifteen protons define phosphorus.
The half-filled 3p subshell gives five valence electrons.
Phosphorus forms rich covalent chemistry and oxidation states from −3 to +5.
Natural phosphorus is essentially one stable isotope.
Structure dramatically changes the behavior of elemental phosphorus.
Phosphorus in its period and family
Phosphorus is in Group 15, Period 3 between silicon and sulfur. Its half-filled 3p³ subshell helps frame its covalent chemistry, but real phosphorus chemistry spans oxidation states from −3 to +5.
Phosphorus Visual Lab
Decode phosphorus’s tile, compare P and P³⁻ shell counts, rotate a ³¹P teaching nucleus and P₄ tetrahedron, inspect 3s/3p probability models, and connect allotropy to phosphate rock, biology, fertilizers and safe evidence-aware chemistry.
Every mark points to one exact feature
The numbered markers explain the same information system used throughout Element Lookup. Unknown or predicted fields remain visibly labelled rather than being replaced with guesses.
Phosphorus in one minute
Atomic number 15 means every phosphorus nucleus contains 15 protons.
Neutral phosphorus has the ground-state configuration [Ne] 3s² 3p³.
³¹P is the only stable natural phosphorus isotope.
White phosphorus consists of P₄ molecules, while red and black phosphorus have different structures.
Most phosphorus in nature occurs in phosphate compounds, not as free elemental phosphorus.
Shell rings organize electron counts. They are not electron trajectories or orbital shapes.
2 · 8 · 5 electrons
The 3s model is spherical and the 3p model uses the p angular form with selectable orientation. These are isolated-atom probability distributions, not pictures of bonds inside P₄ or extended black phosphorus.
White phosphorus consists of tetrahedral P₄ molecules packed in a molecular solid. Red and black phosphorus have different extended structures and are not represented by the same molecular model.. The viewer is evidence-aware: measured structures are identified as such; unknown bulk structures stay unknown.
Teaching visualization; not a literal finite sample or thermal trajectory.What this model does—and does not—show
The 3s model is spherical and the 3p model uses the p angular form with selectable orientation. These are isolated-atom probability distributions, not pictures of bonds inside P₄ or extended black phosphorus.
Where do I meet phosphorus?
Clickable learning cards connect the element to materials, environment, technology, biology or research - depending on what the evidence actually supports.
Biology
Phosphate groups are fundamental to DNA, RNA, ATP, membranes and mineralized tissues.
One element, radically different allotropes
White, red and black phosphorus show how connectivity can matter as much as atomic identity.
P4 molecular solid
White phosphorus contains tetrahedral P4 molecules and is much more reactive than the other common allotropes.
Nitrogen, phosphorus and arsenic
Group 15 shares an ns2np3 valence pattern while elemental structures change from molecular nitrogen to multiple phosphorus and arsenic allotropes.
| Valence | 2s² 2p³ |
|---|---|
| Ordinary form | N₂ gas |
| Valence | 3s² 3p³ |
|---|---|
| Allotropes | white / red / black |
| Stable isotope | ³¹P |
| Valence | 4s² 4p³ |
|---|---|
| Context | metalloid allotropes |
Phosphorus properties: atomic, physical, thermal and chemical
Categories follow the science of this element rather than a fixed decorative template. Each row carries condition/provenance context and an evidence label; unknown values stay unknown.
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Atomic number | 15 | Source-reviewed; see Sources below | Evaluated |
| Relative atomic mass | 30.974 | Source-reviewed; see Sources below | Evaluated |
| Ground-state electron configuration | [Ne] 3s² 3p³ | Source-reviewed; see Sources below | Evaluated |
| Group / period / block | Group 15 · Period 3 · p-block | Periodic-table placement | Evaluated |
| Electronegativity | 2.19 | Source-reviewed; see Sources below | Evaluated |
| Reference isotope | ³¹P | Source-reviewed; see Sources below | Evaluated |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| State context | Solid nonmetal at 20 °C · allotrope-dependent | Source-reviewed; see Sources below | Evaluated |
| Density | 1.823 g/cm³ · white phosphorus reference | Source-reviewed; see Sources below | Evaluated |
| Material / molecular structure | White phosphorus · P₄ molecular solid reference | White phosphorus consists of tetrahedral P₄ molecules packed in a molecular solid. Red and black phosphorus have different extended structures and are not represented by the same molecular model. | Measured |
| Classification | Nonmetal · pnictogen | Periodic-table / chemistry classification | Evaluated |
| Structure-model scope | White phosphorus consists of tetrahedral P₄ molecules packed in a molecular solid. Red and black phosphorus have different extended structures and are not represented by the same molecular model. | Teaching visualization; exact crystallographic coordinates are not implied unless stated. | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Melting / transition reference | 317.3 K · white phosphorus reference | Source-reviewed; see Sources below | Evaluated |
| Boiling / gas reference | 553.7 K · white phosphorus reference | Source-reviewed; see Sources below | Evaluated |
| Phase-path context | This slider uses white phosphorus as an explicit reference path: molecular solid below about 317.3 K, liquid to about 553.7 K, and gas above. Red and black phosphorus have different structures and transformations; the slider does not pretend all phosphorus allotropes share one phase path. | Shared phase registry drives the slider, regions and markers. | Evaluated |
| Condition warning | Temperature and pressure define phase behavior; purity/allotropy may matter. | Teaching condition statement | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Common oxidation states | −3, +3, +5 common | Source-reviewed; see Sources below | Evaluated |
| Ion / common ion context | P³⁻ · in ionic phosphides | Source-reviewed; see Sources below | Evaluated |
| Periodic chemistry context | Phosphorus is in Group 15, Period 3 between silicon and sulfur. Its half-filled 3p³ subshell helps frame its covalent chemistry, but real phosphorus chemistry spans oxidation states from −3 to +5. | Element-specific interpretation | Reviewed |
| Chemistry caution | Elemental form, ions and compounds are distinct chemical objects. | Interpretive teaching rule | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| ³¹P | Stable · essentially 100% natural phosphorus | The teaching nucleus contains 15 protons and 16 neutrons. | Evaluated |
| ³²P | Radioactive · tracer isotope | Used in regulated scientific and medical contexts; it is not part of ordinary natural abundance. | Evaluated |
| Phosphorus isotope identity | One stable natural isotope | The single stable isotope makes natural phosphorus isotope composition unusually simple. | Evaluated |
| Teaching nucleus | ³¹P · 15 protons + 16 neutrons | Reference isotope used in the nucleus model | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Page evidence note | Atomic/isotope values and the white-phosphorus reference data are measured/evaluated. The P₄ viewer represents one white-phosphorus molecule, not every allotrope. Commodity geography refers to phosphate rock, not to free elemental phosphorus. | Evidence summary for this guide | Reviewed |
| Structure evidence | White phosphorus consists of tetrahedral P₄ molecules packed in a molecular solid. Red and black phosphorus have different extended structures and are not represented by the same molecular model. | Measured structure, labelled schematic, prediction or explicit unknown as applicable. | Reviewed |
| Map evidence rule | Real pins are reviewed examples; conceptual layers are used when pins would mislead. | Geography Explorer 2.0 | Reviewed |
| Source set | 3 primary/reference links listed below | Open the Sources section for the actual references. | Reviewed |
Is Phosphorus a solid, liquid or gas? State at temperature
This slider uses white phosphorus as an explicit reference path: molecular solid below about 317.3 K, liquid to about 553.7 K, and gas above. Red and black phosphorus have different structures and transformations; the slider does not pretend all phosphorus allotropes share one phase path.
Where on Earth is Phosphorus found or produced?
Who discovered Phosphorus, and when?
Hennig Brand isolated phosphorus while searching for the philosopher’s stone, making it one of the earliest elements discovered in modern-era chemistry.
Safer forms and better chemical understanding reduced reliance on hazardous white-phosphorus applications.
Industrial fertilizer production made phosphorus central to modern agriculture.
Phosphorus remains essential to biology and food systems, while nutrient loss and recycling are major sustainability questions.
From phosphate rock to phosphorus products: a high-level path
Phosphate rock is mined and beneficiated to concentrate phosphate minerals.
Most fertilizer pathways convert phosphate minerals into plant-available phosphate products rather than isolating elemental phosphorus.
Specialized industry can produce elemental phosphorus under controlled high-temperature conditions; operational details are outside this educational guide.
Use, recovery and nutrient management determine how efficiently phosphorus cycles through agriculture and society.
What is phosphorus used for?
Fertilizers
The largest phosphorus demand is tied to phosphate fertilizers for plant nutrition.
Biological molecules
Phosphate chemistry is central to genetic material, energy transfer and membranes.
Specialty chemicals
Phosphorus compounds are used in flame retardants, food chemistry, metal treatment and many other applications.
Materials research
Different phosphorus allotropes, including black phosphorus, are studied for distinctive electronic and layered-material behavior.
Phosphorus isotopes and natural abundance
³¹P
Stable · essentially 100% natural phosphorusThe teaching nucleus contains 15 protons and 16 neutrons.
³²P
Radioactive · tracer isotopeUsed in regulated scientific and medical contexts; it is not part of ordinary natural abundance.
Phosphorus isotope identity
One stable natural isotopeThe single stable isotope makes natural phosphorus isotope composition unusually simple.
Five-question Phosphorus check
What is phosphorus’s atomic number?
How many valence electrons does neutral phosphorus have?
Which is the only stable natural phosphorus isotope?
What molecular unit is characteristic of white phosphorus?
Which statement is correct?
Phosphorus questions students commonly ask
Each answer starts with the direct fact, then explains the chemistry, evidence or material context so the result is understandable rather than merely memorized.
What is phosphorus’s symbol?
Short answer: Phosphorus has the symbol P.
The symbol P is the standardized chemical abbreviation for element 15. In a chemical formula, P identifies phosphorus atoms; a compound containing P is not automatically the same material as elemental phosphorus.
Key point: P always identifies element 15.
Is phosphorus a metal or nonmetal?
Short answer: Phosphorus is a nonmetal in Group 15.
This guide classifies Phosphorus as a nonmetal · pnictogen. Its periodic position is Period 3, p-block, Group 15. Phosphorus is in Group 15, Period 3 between silicon and sulfur. Its half-filled 3p³ subshell helps frame its covalent chemistry, but real phosphorus chemistry spans oxidation states from −3 to +5.
Key point: Periodic-table classification describes recurring atomic/chemical behavior; it does not make every element in a column physically identical.
How many valence electrons does phosphorus have?
Short answer: Neutral phosphorus has five valence electrons, 3s²3p³.
The neutral-atom ground-state reference used on this page is [Ne] 3s² 3p³. This is an isolated-atom reference: bonding and ion formation can change which outer electrons are present or chemically active. The listed common oxidation-state context is −3, +3, +5 common, which helps connect the atomic configuration to ordinary chemistry without treating electron counting as a single universal rule.
Key point: Electron configuration is a ground-state atomic reference, not a literal picture of every compound.
How many neutrons does common phosphorus-31 have?
Short answer: ³¹P has 15 protons and 16 neutrons.
The page’s teaching nucleus is ³¹P, which contains 15 protons and 16 neutrons. Other isotopes of Phosphorus keep the same 15 protons but have different neutron counts.
Key point: Neutron count is isotope-specific.
What is phosphorus used for?
Short answer: Phosphate compounds are essential in fertilizers and biology, with additional industrial uses in materials and chemical products.
Fertilizers: The largest phosphorus demand is tied to phosphate fertilizers for plant nutrition. Biological molecules: Phosphate chemistry is central to genetic material, energy transfer and membranes. Phosphorus in DNA, phosphate minerals and fertilizers is not elemental white phosphorus. The element’s allotropes and its phosphate chemistry must be kept separate.
Key point: Always distinguish the pure element from the compound, alloy, isotope or device material that actually performs the application.
Are white and red phosphorus the same material?
Short answer: They are allotropes of the same element but have different structures, reactivity and physical behavior.
Phosphorus is element 15, a Group 15 nonmetal with five valence electrons and radically different allotropes. White P₄, red phosphorus and layered black phosphorus show how bonding and structure can transform the behavior of the same element. White phosphorus consists of tetrahedral P₄ molecules packed in a molecular solid. Red and black phosphorus have different extended structures and are not represented by the same molecular model.
Key point: Use the direct answer together with the material, isotope and evidence context shown elsewhere on the page.
Scientific sources for Phosphorus
- Royal Society of Chemistry - Phosphorus
- NIST - Atomic Data for Phosphorus
- USGS - Mineral Commodity Summaries 2026
Questions to ask next about Phosphorus
A good element lesson should lead to the next useful question, not end after a list of facts.
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