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.
Fluorine (F)
Fluorine is element 9, the most electronegative element and a highly reactive Group 17 nonmetal. The core learning distinction is F atom versus F₂ elemental gas versus F⁻ fluoride ion: related labels, very different chemical objects.
Fluorine atomic number, mass, electron configuration and key properties
Fluorine: quick answers
How many protons, neutrons and electrons does fluorine have?
Fluorine’s atomic number is 9, so every fluorine atom has 9 protons, and a neutral atom also has 9 electrons. Its most common natural isotope, fluorine-19, has 10 neutrons (other isotopes have different neutron counts).
What is the symbol for fluorine?
The chemical symbol for fluorine is F.
Is fluorine a solid, liquid or gas at room temperature?
Fluorine is a gas at room temperature (about 25 °C).
What family (group) is fluorine in?
Fluorine is a halogen, in group 17, period 2 of the periodic table.
How many valence electrons does fluorine have?
Fluorine has 7 valence electrons, the electrons in its outer shell, which matches its position in group 17.
What is the electron configuration of fluorine?
The ground-state electron configuration of fluorine is [He] 2s² 2p⁵.
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.
Nine protons define fluorine.
Seven valence electrons leave fluorine one electron short of a closed shell.
The 2s²2p⁵ pattern helps explain fluoride formation and strong bonding.
Fluorine heads the halogens.
Elemental fluorine is a diatomic molecule, not fluoride ion.
Fluorine in its period and family
Fluorine heads Group 17 in Period 2. Its seven valence electrons and very high electronegativity strongly favor electron gain or strongly polar covalent bonding.
Fluorine Visual Lab
Decode fluorine’s tile, compare F and F⁻ shell counts, rotate a ¹⁹F teaching nucleus and F₂ molecule, inspect occupied 2s/2p probability models, and connect electronegativity to fluoride minerals, fluorochemicals and safe species distinctions.
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.
Fluorine in one minute
Atomic number 9 means every fluorine nucleus contains 9 protons.
Neutral fluorine has the ground-state configuration [He] 2s² 2p⁵.
Fluorine is the most electronegative element on the Pauling scale.
Ordinary elemental fluorine is F₂, a pale yellow, extremely reactive gas.
Fluoride F⁻ is a chemically different ion with a closed-shell electron count.
Shell rings organize electron counts. They are not electron trajectories or orbital shapes.
2 · 7 electrons
The occupied 2s and 2p clouds are isolated-atom probability models. pₓ/pᵧ/p_z controls change orientation only. The models do not depict the molecular orbitals of F₂ or electron density in fluoride solids.
At ordinary conditions elemental fluorine is molecular F₂. The structure viewer shows a diatomic teaching model rather than a room-temperature crystal lattice.. 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 occupied 2s and 2p clouds are isolated-atom probability models. pₓ/pᵧ/p_z controls change orientation only. The models do not depict the molecular orbitals of F₂ or electron density in fluoride solids.
Where do I meet fluorine?
Clickable learning cards connect the element to materials, environment, technology, biology or research - depending on what the evidence actually supports.
Fluoride minerals
Fluorine occurs naturally in minerals such as fluorite and fluorapatite, where it is present as fluoride in compounds.
F atom, F2 gas and F- ion must not be confused
Fluorine’s extreme chemistry becomes clearer when the neutral atom, elemental molecule and fluoride ion are separated.
Neutral fluorine atom
An isolated F atom has seven valence electrons; it is not the ordinary bulk elemental material.
Fluorine, chlorine and bromine
All three halogens have seven valence electrons, but molecular size and intermolecular forces change their ordinary physical states.
| Valence | 2s² 2p⁵ |
|---|---|
| Ordinary form | F₂ gas |
| Pauling χ | 3.98 |
| Valence | 3s² 3p⁵ |
|---|---|
| Ordinary form | Cl₂ gas |
| Valence | 4s² 4p⁵ |
|---|---|
| Ordinary form | Br₂ liquid |
Fluorine 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 | 9 | Source-reviewed; see Sources below | Evaluated |
| Relative atomic mass | 18.998 | Source-reviewed; see Sources below | Evaluated |
| Ground-state electron configuration | [He] 2s² 2p⁵ | Source-reviewed; see Sources below | Evaluated |
| Group / period / block | Group 17 · Period 2 · p-block | Periodic-table placement | Evaluated |
| Electronegativity | 3.98 | Source-reviewed; see Sources below | Evaluated |
| Reference isotope | ¹⁹F | Source-reviewed; see Sources below | Evaluated |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| State context | Pale yellow diatomic gas at 20 °C | Source-reviewed; see Sources below | Evaluated |
| Density | 0.001553 g/cm³ · gas reference | Source-reviewed; see Sources below | Evaluated |
| Material / molecular structure | F₂ molecule · ordinary elemental form | At ordinary conditions elemental fluorine is molecular F₂. The structure viewer shows a diatomic teaching model rather than a room-temperature crystal lattice. | Measured |
| Classification | Halogen · nonmetal | Periodic-table / chemistry classification | Evaluated |
| Structure-model scope | At ordinary conditions elemental fluorine is molecular F₂. The structure viewer shows a diatomic teaching model rather than a room-temperature crystal lattice. | Teaching visualization; exact crystallographic coordinates are not implied unless stated. | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Melting / transition reference | 53.48 K | Source-reviewed; see Sources below | Evaluated |
| Boiling / gas reference | 85.04 K | Source-reviewed; see Sources below | Evaluated |
| Phase-path context | At approximately standard pressure, fluorine is solid below about 53.48 K, liquid to about 85.04 K, and gaseous above that point. Ordinary room-temperature elemental fluorine is F₂ gas. | 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 | −1 in ordinary compounds | Source-reviewed; see Sources below | Evaluated |
| Ion / common ion context | F⁻ | Source-reviewed; see Sources below | Evaluated |
| Periodic chemistry context | Fluorine heads Group 17 in Period 2. Its seven valence electrons and very high electronegativity strongly favor electron gain or strongly polar covalent bonding. | Element-specific interpretation | Reviewed |
| Chemistry caution | Elemental form, ions and compounds are distinct chemical objects. | Interpretive teaching rule | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| ¹⁹F | Stable · essentially 100% natural fluorine | The only stable natural fluorine isotope; teaching nucleus has 9 protons and 10 neutrons. | Evaluated |
| ¹⁸F | Radioactive · short-lived positron emitter | Used in regulated PET imaging chemistry; it is not part of ordinary natural fluorine abundance. | Evaluated |
| Fluorine isotope identity | One stable natural isotope | Natural fluorine’s stable-isotope composition is essentially all ¹⁹F. | Evaluated |
| Teaching nucleus | ¹⁹F · 9 protons + 10 neutrons | Reference isotope used in the nucleus model | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Page evidence note | Atomic and ordinary phase values are measured/evaluated. The molecule viewer is a simple F₂ teaching model. Resource geography concerns fluoride minerals/fluorspar; it does not imply natural free fluorine gas at those places. | Evidence summary for this guide | Reviewed |
| Structure evidence | At ordinary conditions elemental fluorine is molecular F₂. The structure viewer shows a diatomic teaching model rather than a room-temperature crystal lattice. | 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 Fluorine a solid, liquid or gas? State at temperature
At approximately standard pressure, fluorine is solid below about 53.48 K, liquid to about 85.04 K, and gaseous above that point. Ordinary room-temperature elemental fluorine is F₂ gas.
Where on Earth is Fluorine found or produced?
Who discovered Fluorine, and when?
André-Marie Ampère proposed that hydrofluoric acid contained an unknown element related to chlorine.
Henri Moissan isolated elemental fluorine after decades of difficult and dangerous attempts by chemists.
Fluorine chemistry expanded into refrigerants, polymers, uranium processing, pharmaceuticals and specialty materials.
Fluorine-containing compounds are widespread in modern technology, while some fluorochemical classes receive increasing environmental scrutiny.
From fluoride minerals to fluorine chemistry: a high-level path
Fluorine is sourced from fluoride-bearing minerals, especially fluorspar, rather than from natural F₂ gas.
Industrial processing converts mineral fluoride into feed chemicals under tightly controlled conditions.
Specialized plants produce elemental fluorine or fluorinated intermediates for defined uses; this page intentionally omits operating procedures.
Final products include fluoropolymers, inorganic fluorides, pharmaceuticals and many other chemically distinct materials.
What is fluorine used for?
Fluoropolymers
Strong C-F bonding contributes to low surface energy and chemical resistance in materials such as PTFE.
Inorganic fluorides
Fluoride compounds are used in metallurgy, glass processing and specialized chemical manufacture.
Pharmaceuticals
Fluorine atoms appear in many medicines because substitution can alter molecular properties.
Nuclear fuel-cycle chemistry
UF₆ provides a volatile uranium compound used in enrichment technology; operational enrichment details are outside scope.
Fluorine isotopes and natural abundance
¹⁹F
Stable · essentially 100% natural fluorineThe only stable natural fluorine isotope; teaching nucleus has 9 protons and 10 neutrons.
¹⁸F
Radioactive · short-lived positron emitterUsed in regulated PET imaging chemistry; it is not part of ordinary natural fluorine abundance.
Fluorine isotope identity
One stable natural isotopeNatural fluorine’s stable-isotope composition is essentially all ¹⁹F.
Five-question Fluorine check
What is fluorine’s atomic number?
How many valence electrons does neutral fluorine have?
What is ordinary elemental fluorine?
Which statement is correct?
What is fluorine’s characteristic oxidation state in ordinary compounds?
Fluorine 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 fluorine’s symbol?
Short answer: Fluorine has the symbol F.
The symbol F is the standardized chemical abbreviation for element 9. In a chemical formula, F identifies fluorine atoms; a compound containing F is not automatically the same material as elemental fluorine.
Key point: F always identifies element 9.
Is fluorine a metal?
Short answer: No. Fluorine is a nonmetal halogen in Group 17.
This guide classifies Fluorine as a halogen · nonmetal. Its periodic position is Period 2, p-block, Group 17. Fluorine heads Group 17 in Period 2. Its seven valence electrons and very high electronegativity strongly favor electron gain or strongly polar covalent bonding.
Key point: Periodic-table classification describes recurring atomic/chemical behavior; it does not make every element in a column physically identical.
What is fluorine used for?
Short answer: Fluorine chemistry appears in fluoropolymers, inorganic fluorides, medicines and specialized industrial processes.
Fluoropolymers: Strong C-F bonding contributes to low surface energy and chemical resistance in materials such as PTFE. Inorganic fluorides: Fluoride compounds are used in metallurgy, glass processing and specialized chemical manufacture. Fluoride in minerals, water or toothpaste is not elemental fluorine gas. Fluorine’s usefulness and hazards make sense only when the chemical species is identified correctly.
Key point: Always distinguish the pure element from the compound, alloy, isotope or device material that actually performs the application.
Is fluoride the same as fluorine gas?
Short answer: No. F⁻ fluoride is an ion in compounds and solutions; F₂ is elemental fluorine gas and is far more reactive.
Fluoride in minerals, water or toothpaste is not elemental fluorine gas. Fluorine’s usefulness and hazards make sense only when the chemical species is identified correctly. Inorganic fluorides Fluoride compounds are used in metallurgy, glass processing and specialized chemical manufacture.
Key point: The pure element, its ions, compounds and alloys are different materials and should not be treated as interchangeable.
Why is fluorine so reactive?
Short answer: Elemental fluorine, F₂, is an exceptionally strong oxidizing reagent because reactions that transfer electron density toward fluorine often form very stable fluorides.
The explanation is more complete than “fluorine wants one electron.” Fluorine atoms are small and highly electronegative, and many bonds formed to fluorine are strong. Meanwhile the F–F bond is not unusually strong for a halogen bond. Together these factors make many oxidation reactions with F₂ strongly favorable. Keep the chemical objects distinct: neutral F atoms, F₂ molecules and F⁻ ions do not have the same properties.
Key point: Reactivity is a property of a reacting chemical species under conditions; for elemental fluorine, combine F₂ bond energetics with the strong stability of many fluoride products.
What is fluorine’s electron configuration?
Short answer: [He] 2s² 2p⁵. That gives seven valence electrons.
The neutral-atom ground-state reference used on this page is [He] 2s² 2p⁵. 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 −1 in ordinary compounds, 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 valence electrons does fluorine have?
Short answer: Seven. Fluorine ends in 2s² 2p⁵, leaving it one electron short of a closed second shell.
The neutral-atom ground-state reference used on this page is [He] 2s² 2p⁵. 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 −1 in ordinary compounds, 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.
Scientific sources for Fluorine
- Royal Society of Chemistry - Fluorine
- NIST - Atomic Data for Fluorine
- USGS - Mineral Commodity Summaries 2026
- RSC — Fluorine
Questions to ask next about Fluorine
A good element lesson should lead to the next useful question, not end after a list of facts.
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