literature

The History of Fluoridation - What is Fluorine?

Deviation Actions

Published: Aug 24, 2015

805 Views

Literature Text

Fluorine (Atomic Number 9)

The Fluorine atom is a Halogen that appears as a pale yellow gas. This gas is corrosive enough to destroy borosilicate glass [1].

Fluorine is the first and lightest Halogen on the Periodic table.
The others being (In order) Chlorine (CI), Bromine (Br), Iodine (I), and Astatine (At) [2].
Fluorine is also the most Electronegative element out of all the elements in the periodic table [3] [4]

Fluorine reacts directly with all elements, except Helium (He), Neon (Ne) and Argon (Ar) [3].
The lighter Noble Gases Xenon (Xe) and Krypton (Kr) can react directly with Fluorine, but only under special conditions [5].
For example, Fluorine can react with the noble gas Xenon and form the strong agent, Xenon Difluoride (XeF₂) [3].

Fluorine's first Ionization (ion) energy (The Energy required to remove an electron, to make the diatomic molecule F⁺) is 1,681 kilojoules (Joule) per mole, which is higher than for any other element except Neon and Helium [6].
What is the difference between Compounds and Molecules?

A molecule is a combination of two or more Atoms that are held together by Covalent Bonds. Molecules may contain two atoms of the same element, such as O₂ and H₂, or they may consist of two or more different atoms, such as H₂O [7].

However, a Compound is always a combination of different elements [8] [9].
Both the element Fluorine and the Fluoride ion are highly toxic.
The recommended maximum allowable concentration for a daily 8-hour time-weighted exposure is 0.1 ppm.

Free fluorine has a characteristic pungent odor, detectable at concentrations as low as 20 ppb [1].
The immediately dangerous to life or health concentration of Fluorine is 25 ppm (Hydrogen Cyanide, in contrast, is 50 ppm) [10].
"Odour Detection Threshold": This is the lowest concentration of a certain odour compound
that is perceivable by the human sense of smell [11].

“Lowest Observed Adverse Effect Level” (LOAEL): This is the lowest concentration or amount of a substance found by experiment or observation that causes an adverse alteration of morphology, function, capacity, growth, development, or lifespan of a target organism distinguished from normal organisms of the same species under defined conditions of exposure [12].

The difference between Fluorine & Fluoride

Fluoride is the negative ion of the element Fluorine (Atomic Number: 9) [13]. When Fluorine forms a Binary Compound with another element or radical, that compound then becomes a Fluoride and then named after the Fluoride atom (e.g., Bifluoride, HF2-).

Note:
The Fluorine atom is often written as F- [14]
Fluorides can be either Organic or Inorganic compounds which contain the element Fluorine.
Different examples of Fluorides:
Hydrofluoric acid (HF), Sodium Fluoride (NaF) and Calcium Fluoride (CaF₂) and Uranium Hexafluoride (UF₆).
Being a Halogen, Fluorine forms one monovalent bond (1^- charge), with another element.

Halogens

Halogens are the only periodic group of elements that share all three familiar states of matter at the same given temperature and pressure (STD) [15] [16].

The Halogens can be found on the left-hand side of the Noble-gases [3] in the Periodic table, and are all toxic [15]. As such, they can be harmful or lethal to biological organisms in sufficient quantities [17].

The name "Halogen" is derived from it's Greek roots hal- (Which means "salt") and -gen (Which means "to form"). Together these words combine to mean "salt former", which is in reference to the fact that Halogens form salts when they react with metals.
Halite is the mineral name for rock salt, which is a natural mineral consisting essentially of Sodium Chloride (NaCl) [00].

Fluorine is one of the most reactive elements in existence, attacking otherwise-inert materials such as glass and forming compounds with the heavier Noble gases [17].

Noble Gases

The Noble gases are a group of chemical elements with very similar properties: Under standard conditions (STP), they are all odorless, colorless, monatomic gases, with very low chemical reactivity. Because their outer shell of Valence Electrons are considered to be full.
The six noble gases that occur naturally are He, Ne, Ar, Kr, Xe, and the radioactive Rn [18].

Inert Gas

The term Inert gas is context-dependent because Nitrogen gas and several other Noble Gases can be made to react under certain conditions. Unlike Noble gases, an Inert gas is not necessarily elemental and is often a compound gas.

Like the Noble Gases, the tendency for non-reactivity is due to the valence, the outermost electron shell, being complete in all Inert gases. This is a tendency, not a rule, as Noble gases and other "Inert" gases can react to form compounds [19].