Editing Period 2 element (section)

===Fluorine===
{{main article|Fluorine}}
[[File:Liquid fluorine tighter crop.jpg|thumb|left|150px|Liquid fluorine in ampoule]]

Fluorine is the chemical element with atomic number 9. It occurs naturally in its only stable form <sup>19</sup>F.<ref>{{cite web |author=National Nuclear Data Center |title=NuDat 2.1 database – fluorine-19 |url=http://www.nndc.bnl.gov/nudat2/reCenter.jsp?z=9&n=10 |publisher=[[Brookhaven National Laboratory]] |access-date=2011-05-01}}</ref>

Fluorine is a pale-yellow, diatomic gas under normal conditions and down to very low temperatures. Short one electron of the highly stable octet in each atom, fluorine molecules are unstable enough that they easily snap, with loose fluorine atoms tending to grab single electrons from just about any other element. Fluorine is the most reactive of all elements, and it even attacks many oxides to replace oxygen with fluorine. Fluorine even attacks silica, one of the favored materials for transporting strong acids, and burns asbestos. It attacks [[sodium chloride|common salt]], one of the most stable compounds, with the release of chlorine. It never appears uncombined in nature and almost never stays uncombined for long. It burns hydrogen simultaneously if either is liquid or gaseous—even at temperatures close to absolute zero.<ref>{{cite web|url=https://www.webelements.com/fluorine/|title=WebElements Periodic Table » Fluorine » the essentials|website=www.webelements.com}}</ref> It is extremely difficult to isolate from any compounds, let alone keep uncombined.

Fluorine gas is extremely dangerous because it attacks almost all organic material, including live flesh. Many of the binary compounds that it forms (called fluorides) are themselves highly toxic, including soluble fluorides and especially [[hydrogen fluoride]]. Fluorine forms very strong bonds with many elements. With sulfur it can form the extremely stable and chemically inert [[sulfur hexafluoride]]; with carbon it can form the remarkable material [[Teflon]] that is a stable and non-combustible solid with a high melting point and a very low coefficient of friction that makes it an excellent liner for cooking pans and raincoats. Fluorine-carbon compounds include some unique plastics.
it is also used as a reactant in the making of toothpaste.