<?xml version="1.0" encoding="utf-8"?><mads xmlns="http://www.loc.gov/mads/" xmlns:mods="http://www.loc.gov/mods/v3" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.loc.gov/mads/
mads.xsd"><authority><topic authority="http://AATesaurus.cultura.gencat.cat/aat/getty_en">fluorine</topic></authority><related type="broader"><topic>fluorine and fluorine compounds</topic></related><related type="broader"><topic>elements</topic></related> <note xml:lang="en"><![CDATA[ Chemical element that, when pure, is a pale-yellow, toxic gas. Fluorine occurs naturally in the form of mineral fluorite, cryolite, and fluorapatite. Fluorine is the most electronegative and reactive element known. Henri Moissan of France received a Nobel Prize for first isolating fluorine in 1886.  ]]></note></mads>