Fluorine (symbol F) is a special type of matter called a chemical element. It's known for being very reactive and can be dangerous. Its atomic number is 9, meaning it has 9 protons in its center. Fluorine is part of Group 17 on the periodic table, which are known as the halogens.

What Is Fluorine Like?
- Temperature Points
- Fluorine Compounds
Where Is Fluorine Found?
How Is Fluorine Made?
What Is Fluorine Used For?
Safety Information
Related Topics
Images for kids
See also

What Is Fluorine Like?

Fluorine is a light yellow gas. It is made of two fluorine atoms joined together, called a diatomic molecule. This element is the most reactive of all known elements. It really loves to grab electrons from other atoms. This makes it a very strong oxidizing agent.

Fluorine can even take electrons from water, which creates oxygen gas. It can also make propane burst into flames without needing a spark. Even metals can catch fire when exposed to fluorine gas. When fluorine reacts with other things, it forms a stable particle called a fluoride ion.

Temperature Points

Fluorine needs to be very cold to change its state. It melts at about -363.33°F (-219.62°C). It boils, turning into a gas, at about -306.62°F (-188.12°C).

Fluorine Compounds

Chemical compounds that contain fluorine are called fluorides. In these compounds, fluorine always has a special charge of -1. Some common examples of fluorine compounds include:

Hydrofluoric acid: This is a strong acid made from hydrogen fluoride dissolved in water.
Hydrogen fluoride: A gas that is very corrosive.
Sodium fluoride: Often found in toothpaste.
Sulfur hexafluoride: A gas used in many industrial applications.
Tin(II) fluoride: Another compound sometimes used in dental products.

Where Is Fluorine Found?

Fluorite crystals, a common source of fluorine.

You won't find pure fluorine as an element on Earth. It's far too reactive! Instead, it's always found combined with other elements in compounds called fluorides.

Many fluorides are found naturally in the Earth's crust. They are in rocks, coal, and clay. One important mineral that contains fluorine is fluorite.

How Is Fluorine Made?

Most fluorine is made using a process called electrolysis. This involves dissolving hydrogen fluoride in potassium fluoride. Then, an electric current is passed through this melted mixture. This process separates the hydrogen and fluorine. Hydrogen forms on one side, and fluorine forms on the other. It's very important to keep these two sides separate, or the setup could explode!

In 1986, a scientist managed to make fluorine without using electrolysis. They used different chemical compounds to create manganese(IV) fluoride, which then released fluorine gas.

What Is Fluorine Used For?

Fluorine and its compounds have many important uses:

Nuclear Energy: Fluorine is used to prepare uranium for nuclear weapons and nuclear power.
Industrial Gas: It helps make sulfur hexafluoride, a gas used in electrical equipment.
Electronics: Fluorine is important in making integrated circuits, which are tiny parts of computers and phones.
Everyday Products:
- Fluoride ions are added to many toothpastes to help prevent cavities.
- Some fluorine compounds are used to create nonstick coatings for pans.
- Older Freons, which were used in refrigerators and air conditioners, also contained fluorine.

Safety Information

Pure fluorine gas is extremely reactive and very dangerous. It can react with almost anything, even glass. It is also highly poisonous.

Fluoride ions, which are found in fluorine compounds, are less dangerous but can still be toxic if too much is consumed. For example, eating too much toothpaste with fluoride could cause fluoride poisoning. However, fluoride ions are not as reactive as pure fluorine gas.

Images for kids

Fluorine 3D molecule
Animation showing the crystal structure of beta-fluorine. Molecules on the faces of the unit cell have rotations constrained to a plane.
Steelmaking illustration from De re metallica
1887 drawing of Moissan's apparatus
An ampoule of uranium hexafluoride
Chlorine trifluoride, whose corrosive potential ignites asbestos, concrete, sand and other fire retardants
These xenon tetrafluoride crystals were photographed in 1962. The compound's synthesis, as with xenon hexafluoroplatinate, surprised many chemists.
Immiscible layers of colored water (top) and much denser perfluoroheptane (bottom) in a beaker; a goldfish and crab cannot penetrate the boundary; quarters rest at the bottom.
Industrial fluorine cells at Preston
SF₆ current transformers at a Russian railway.
Fluorosurfactant-treated fabrics are often hydrophobic
Topical fluoride treatment in Panama
The gifblaar is one of the few organofluorine-synthesizing organisms
NASA projection of stratospheric ozone over North America without the Montreal Protocol
Perfluorooctanesulfonic acid, a key Scotchgard component until 2000
Fluorite: Pink globular mass with crystal facets
Fluorapatite: Long prism-like crystal, without luster, at an angle coming out of aggregate-like rock
Cryolite: A parallelogram-shaped outline with diatomic molecules arranged in two layers