Fluorine gas is extremely reactive, yet fluorine-containing compounds can have very different properties. Fluorine chemistry produces materials such as PTFE, used for non-stick surfaces and insulation. This contrast makes chemical form essential: an element's identity alone does not describe a substance's behavior.
FROM ELEMENT TO APPLICATION
AN ELEMENT IN CONTEXT
Why can a fluorine-containing polymer behave unlike elemental fluorine?
PTFE, a fluorine-containing polymer
FOLLOW THIS RELATIONSHIP
Identify the polymer form
PTFE contains fluorine chemically bonded within a carbon-based polymer; its material surface is therefore not a reservoir of free elemental fluorine gas.
Explore the model (optional)
FFORM → INTERACTION → CONSEQUENCE
Follow the explanation in either direction. These are authored steps, not a physical clock.
Atomic identity, reference properties and structure models
INTERACTIVE 3D2 visible sites
F₂ · two atoms, one moleculeDrag to rotate · scroll or pinch to zoom
An elemental molecule has more than one atom but only one element. A single connector identifies the molecular pair; bond order and electron density are not encoded.
What this representation means
Original idealized molecular geometry. Display sizes are illustrative; this is not a measured coordinate dataset.
Chemists recognized that fluorides contained an unidentified element before they could isolate it. Ampère proposed the name fluorine in 1812, but the substance's strong reactivity frustrated experiments and damaged equipment. Moissan finally obtained elemental fluorine in 1886. This history makes the distinction between recognizing an element in a compound and obtaining the free element especially clear; it also records the hazards of early laboratory practice.
1812
Name proposed
Ampère introduced the name fluorine for the suspected element.
1886
Element isolated
Moissan obtained elemental fluorine after earlier unsuccessful attempts by other investigators.
Fluorine occurs naturally in fluoride-containing , including fluorite, rather than as a reservoir of free fluorine gas. Industrial fluorine chemistry starts from such compounds. The fluorine atoms in a mineral, a specialized , and a fluoride salt belong to the same element but occupy different chemical environments.
Fluorine gas is highly reactive, whereas some fluorine-containing materials are valued for chemical resistance. This apparent contrast disappears when the actual substance is identified: bonds in a compound determine its behavior. Fluorine gas, fluoride , and carbon-fluorine bonds should not be treated as interchangeable descriptions.
Each section links its supporting references. Descriptions and diagrams were authored for this atlas. Source checks completed. Source checks dated 2026-09-06.
CITE THIS PAGE
Family labels and the group-3 layout are teaching conventions. A table position does not establish an unknown bulk property. Electronic configurations refer to neutral atoms; ions and material environments require their own account.
Read each reference property together with its units, conditions and the reference information below.
Not yet recorded: electron affinity, second ionization energy, ground-state term symbol, van der waals radius, thermal conductivity, specific heat capacity, electrical resistivity, crystal structure, lattice parameter a, space group, abundance in seawater, abundance in the universe, annual production, supply-risk listing, hazard classification, biological role, cas registry number, pubchem cid, wikidata item. These families are declared and awaiting an ingestion run against the source each names; they are listed here rather than shown as empty rows.
Physical
Intended reference: CRC Handbook of Chemistry and Physics · CRC Press
Phase at 20 °C
gas
293.15 K, 101.325 kPa
Melting point in K
53.48 K
at standard pressure unless noted
Boiling point in K
85.03 K
101.325 kPa
Density in g/cm³
0.0017 g/cm³
solids and liquids at 293 K; gases at 273 K and 101.325 kPa
Atomic and electronic
Intended reference: Pauling electronegativity scale · Widely tabulated; original in The Nature of the Chemical Bond
Electronegativity in Pauling
3.98 Pauling
Pauling scale
First ionization energy in kJ/mol
1681 kJ/mol
gas-phase neutral atom, ground state
Covalent radius in pm
57 pm
single-bond covalent radius
Common oxidation states
-1
states met in ordinary compounds; not exhaustive
Occurrence and identity
Intended reference: CRC Handbook of Chemistry and Physics · CRC Press
Abundance in the crust in mg/kg
585 mg/kg
upper continental crust, mass fraction
Has stable isotopes
Yesderived
Discovery year in CE
1886 CEderived
WHERE IT SITS AMONG ITS NEIGHBORS
Electronegativity across period 2
F 3.98 Pauling · Fluorine
Electronegativity across period 2. Exact values.
Li
0.98
Be
1.57
B
2.04
C
2.55
N
3.04
O
3.44
F
3.98
Electronegativity down group 17
F 3.98 Pauling · Fluorine
Electronegativity down group 17. Exact values.
F
3.98
Cl
3.16
Br
2.96
I
2.66
At
2.2
The trend uses the same reference-property values as the periodic table. Elements with no recorded value are left out of the line rather than drawn at zero.
