22.3+-+Group+8+The+Noble+Gases



__**Noble Gases:**__ These are the elements of Group 8A. Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), Radon (Rn) make up the Noble Gases.Noble Gases are chemically unreactive due to the presence of a completed octet of valence-shell electrons (except He, which has a filled 1s shell). Relative to the periodic trend, Noble Gases have high ionization energies and this is due to the complete octet of valence electrons. All of these gases are indeed gases at room temperature.

Helium is probably the most important Noble Gas. Liquid helium is used as a coolant to conduect experiments at very low temperatures. Helium has the lowest boiling point of any substance - 4.2K under 1 atm pressure. Relatively high concentrations of helium is found in many natural gas wells.
 * Helium (He):**

Neon is a very common element in the universe but quite rare on earth. Neon has a distinct Redish-Orange glow when used in low-voltage discharge tubes, otherwise known as neon advertising signs. It is commercially extracted from air in which it is found in trace amounts.
 * Neon (Ne):**

Argon is the most abundant Noble Gas on earth. Argon is used as a blanketing atmosphere in electric lightbulbs. The gas conducts heat away from the filament but does not react with it. It is also used as a protective atmosphere to prevent oxiddation in welding and certain high-temperature metallurgical processes.
 * Argon (Ar):**

Krypton is a colorless, oderless, tasteless noble gas. One can find krypton in trace amounts in earth's atmosphere. To extract krypton and most noble gases, isolation by distilling liquified air must occur. Krypton is normally used with other rare gases in fluorescent lamps. Krypton light has a large number of spectral lines, and krypton's high light output in plasmas allows it to play an important role in many high-powered gas lasers, which pick out one of the many spectral lines to amplify.
 * Krypton (Kr):**

Xenon produces a brilliant white flash of light when it is excited electrically and is widely used in strobe lights. The light emitted from xenon lamps is also used to kill bacteria and to power ruby lasers. Due to its high atomic weight, xenon ions were used as a fuel in an experimental ion engine aboard the space probe Deep Space 1. Xenon was discovered through the process of liquified air. Xenon makes up 0.0000087% of earth's atmosphere.
 * Xenon (Xe):**

Radon is by far the most dangerous noble gas. It is very radioactive and causes many health hazards such as cancer. Radon is a natural decay product of uranium and is one of the densest substances that remains gas under standard conditions. Its most stable isotope, 222Rn, has a half-life of 3.8 days. Due to its intense radioactivity, it has been less well-studied by chemists, but a few compounds are known. __**Noble Gas Compounds:**__ Because noble gases are so stable, the only way for a noble gas to undergo reaction is only under rigorous conditions. We can assume that the heavier nobles gases would be most likely to form compounts because their ionization energies are lower. Lower ionization energies suggest possiblities of sharing electrons with another atom that leads to chemical bonding. Because all 8A elements, except He, have their octet of valence electrons in their valence shell, covalent bonds will require an expanded valence shell. You will only see an expansion in the valence shell in larger atoms.
 * Radon (Rn):**

Clathrates (also known as cage compounds) are compounds of noble gases in which they are trapped within cavities of crystal lattices of certain organic and inorganic substances.
 * Clathrates: **

Coordination compounds such as Ar·BF3 have been postulated to exist at low temperatures, but have never been confirmed.
 * Coordination Compounds: **

Hydrates are formed by compressing the noble gases in water. It is believed that the water molecule, a strong dipole, induces a weak dipole in the noble gas atoms, resulting in dipole-dipole interaction.
 * Hydrates: **

Helium- None found Neon- None found Argon- HArF found in 2000 Krypton- KrF2 Xenon- Xenon has multiple multiple compounds with oxygen, fluorine, nitrogen, carbon, and even gold Radon- RnF2
 * True noble gas compounds: **

[|**http://www.youtube.com/watch?v=QLrofyj6a2s**]
 * Video with overview of Noble Gases:**


 * A more detailed overview of Noble Gases:**
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 * IMO learn this rap (it will help):**
 * []**


 * Sources:**
 * Brown-Lemay AP Chem Edition 11 Textbook**
 * Authors, Many. "Krypton." //Wikipedia, the Free Encyclopedia//. Web. 24 Mar. 2011. [].**
 * Gagnon, Steve. "It's Elemental - The Element Xenon." //Science Education at Jefferson Lab//. Web. 24 Mar. 2011. [].**
 * Sources, Many. "Neon." //Wikipedia, the Free Encyclopedia//. Web. 24 Mar. 2011. [].**


 * Sources, Many. "Noble Compounds." //Wikipedia, the Free Encyclopedia.// Web.24 Mar 2011. [].**


 * Sources, Many. "Radon." //Wikipedia, the Free Encyclopedia//. Web. 24 Mar. 2011. [].**