from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A pale-yellow, highly corrosive, poisonous, gaseous halogen element, the most electronegative and most reactive of all the elements, used in a wide variety of industrially important compounds. Atomic number 9; atomic weight 18.9984; freezing point -219.62°C; melting point -223°C; boiling point -188.14°C; specific gravity of liquid 1.108 (at boiling point); valence 1. See Table at element.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The chemical element (symbol F) with an atomic number of 9.
- n. A fluorine atom.
from the GNU version of the Collaborative International Dictionary of English
- n. A non-metallic, gaseous element of atomic number 9, strongly acid or negative, and associated with chlorine, bromine, and iodine, in the halogen group of which it is the first member. It always occurs combined, is very active chemically, and possesses such an avidity for most elements, and silicon especially, that it can neither be prepared nor kept in glass vessels, but may be contained in lead vessels. If set free it immediately attacks a containing glass vessel, so that it was not isolated until 1886. It is a pungent, corrosive, colorless gas. Symbol F. Atomic weight 19.00.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a nonmetallic univalent element belonging to the halogens; usually a yellow irritating toxic flammable gas; a powerful oxidizing agent; recovered from fluorite or cryolite or fluorapatite
"The new mineral does not contain fluorine and is white rather than green, but in all other respects the chemistry matches that for the rock containing kryptonite," Stanley said.
It's a corrosive gas, like fluorine, which is used to etch glass.
At a red heat platinic fluoride decomposes into metallic platinum and fluorine, which is evolved in the free state.
This is a compound of fluorine, which is actually a chemical byproduct of aluminum, steel, cement, phosphate, and other assorted ingredients.
To divert to the outer planets for a moment, Titan, one might note (together with giant bodies like Jupiter and Saturn to boot), is in a wholly unoxygenating (or “reducing”) environment (no oxygen, nor any other reactive gas such as fluorine or chlorine anywhere around).
While most of the requirements for keeping people alive are common (mainly hydrogen, carbon, oxygen, nitrogen, calcium, and phosphorus) and are fairly easy to handle, there is a long list of trace elements that human body requires, some of which are not easy to handle (such as fluorine) and even harder to get into forms that the human body can assimilate.
Generally, indeed, it may be maintained that right is of a nature analogous to that of certain chemical substances, which cannot be exhibited in a pure and isolated condition, but at the most only with a small admixture of some other substance, which serves as a vehicle for them, or gives them the necessary consistency; such as fluorine, or even alcohol, or prussic acid.
Hekla, Iceland: 14 May 1970; "Local groundwater is measuring high amounts of fluorine, which is toxic to sheep and horses.
In the past some such eruptions have contained fluorine which is dangerous to livestock and to people if it settles on crops, for example.
In this instance, anti-fluoridationists fixated on the dangers of fluorine, a poisonous gas that is among the most chemically reactive of all elements.