Category: Halogen
Atomic Number: 9
Period: 2 | Group: 17
Block: p-block
The most electronegative element known: fluorine takes electrons from almost anything, including glass and water.
| Property | Value |
|---|---|
| Phase at STP | Gas |
| Density | 0.00169630 g/cm³ |
| Melting Point | 53.48 K (-219.67 °C) |
| Boiling Point | 85.03 K (-188.12 °C) |
| Heat Capacity | N/A |
| Property | Value |
|---|---|
| Atomic Mass | 18.9980 u |
| Electronegativity (Pauling) | 3.98 |
| Oxidation States | -1 |
| Electron Configuration | [He] 2s² 2p⁵ |
| Discovered By | Henri Moissan |
|---|---|
| Discovery Year | 1886 |
| Named After | Latin fluere, "to flow" |
| ISOTOPE | Neutrons | Natural Abundance | Half-life | Decay Mode |
|---|---|---|---|---|
| F-18 | 9 | - | 109.77 min | ε/β⁺ |
| F-19 | 10 | 100% | Stable | - |
Data: IAEA Nuclear Data Section, LiveChart of Nuclides, ground-state evaluations, retrieved October 10, 2026. Abundance is the share of atoms in the natural element; a dash means the isotope has no standard natural abundance.
Industrial Applications and Manufacturing
Uranium Enrichment and Nuclear Industry
The largest industrial use of fluorine is in uranium hexafluoride (UF₆) production for nuclear fuel enrichment:
Gas diffusion method - UF₆ is processed through selective barriers to concentrate U-235
Gas centrifuge enrichment - High-speed centrifuges separate isotopes based on mass differences
Nuclear fuel fabrication - Enriched uranium is converted back to uranium dioxide for reactor fuel
Fluorine gas production - Electrolysis of anhydrous hydrogen fluoride produces pure fluorine
Nuclear waste processing - Fluorine compounds help recover valuable materials from spent fuel
Fluoropolymer Manufacturing
Fluorine creates exceptionally durable and chemically resistant polymers:
Polytetrafluoroethylene (PTFE/Teflon) - Non-stick cookware, gaskets, and chemical-resistant linings
Fluorinated ethylene propylene (FEP) - Wire insulation and chemical processing equipment
Perfluoroalkoxy (PFA) - High-purity semiconductor manufacturing equipment
Polyvinylidene fluoride (PVDF) - Architectural membranes and chemical plant piping
Fluoroelastomers (Viton) - High-temperature seals for aerospace and automotive applications
Refrigeration and Air Conditioning
Fluorinated compounds transformed cooling technology:
Hydrofluorocarbons (HFCs) - R-134a, R-410A, and other refrigerants for HVAC systems
Hydrofluoroolefins (HFOs) - Next-generation low-GWP refrigerants like R-1234yf
Perfluorocarbons (PFCs) - Specialized refrigerants for very low-temperature applications
Foam blowing agents - Create insulating foams for refrigerators and building insulation
Heat pump applications - Enable efficient heating and cooling systems
Electronics and Semiconductor Industry
Fluorine compounds are essential for modern electronics manufacturing:
Plasma etching - CF₄, SF₆, and NF₃ etch silicon wafers with atomic precision
Chamber cleaning - Fluorine-based gases clean chemical vapor deposition reactors
Dielectric materials - Fluorinated polymers provide electrical insulation in microchips
Lithium battery electrolytes - Fluorinated solvents improve battery performance and safety
Photolithography - Fluorinated resists enable extreme ultraviolet (EUV) semiconductor manufacturing
Pharmaceutical and Agrochemical Industry
Fluorine dramatically enhances drug and pesticide properties:
Fluorinated pharmaceuticals - 20% of drugs contain fluorine, including antidepressants and antibiotics
Positron emission tomography - Fluorine-18 isotope enables medical imaging
Anesthetics - Sevoflurane and desflurane provide safe surgical anesthesia
Agricultural pesticides - Fluorinated compounds improve pesticide effectiveness and selectivity
Veterinary medicines - Fluoroquinolone antibiotics treat animal infections
Metal Surface Treatment
Fluorine compounds provide superior surface protection:
Aluminum surface preparation - Fluoride-containing etchants clean and etch aluminum before finishing
Stainless steel pickling - Removes oxide scales and improves corrosion resistance
Glass etching - Hydrogen fluoride creates decorative and functional glass surfaces
Silicon wafer polishing - Fluorine-based solutions create atomically smooth surfaces
Metal cleaning - Removes rust, scale, and contaminants from metal surfaces
Aerospace and Defense Applications
Fluorine compounds enable extreme-environment technologies:
Rocket propellants - Fluorine-based propellants gave the highest specific impulse ever test-fired, but have never flown on a space mission
Hypersonic vehicle cooling - Fluorocarbon coolants withstand very high temperatures
Satellite components - Fluoropolymers resist radiation and large temperature cycling
Military applications - Specialized fluorine compounds for defense technologies
Space suit materials - Fluorinated fabrics provide chemical and UV protection
Fluorite, cryolite, fluorapatite
| Earth's Crust | 0.0005850000 ppm |
|---|---|
| Universe | 0.0000000400 % |