86
Rn
(222)
Radon
Average radioactivity intensity in the world's atmosphere caused by radon.
Classification: Radon is a noble gas and a nonmetal
Color: colorless
Atomic weight: (222), no stable isotopes
State: gas
Melting point: -71 oC, 202 K
Boiling point: -62 oC, 211 K
Shells: 2,8,18,32,18,8
Electron configuration: [Xe] 4f14 5d10 6s2 6p6
Density @ 20oC: 0.00973 g/cm3
Atomic volume: 50.5 cm3/mol
Structure:

Discovery of Radon


Radon gas was discovered in 1900 by Fredrich E. Dorn. He described it as radium emanation because it arose from the element radium, which he was working with.

In 1908 William Ramsay and Robert Gray isolated the gas and named it niton.

Since 1923, it has been called radon (after radium, one of its sources).

Radon was one of the earliest discovered radioactive elements, identified after uranium, thorium, polonium and radium.




Appearance & Characteristics

Radon is the number one hazard in the home.


Harmful effects:
Radon is highly radioactive and a carcinogen. Its decay products are toxic and radioactive. Radon is present in most homes and is the number one cause of lung-cancer in non-smokers in the USA. (See video on left.)

Characteristics:
Radon is one of the noble gases; hence it is a chemically inert, monatomic gas. It is also radioactive, colorless and odorless.

Radon is produced naturally by the decay of uranium's decay products, such as 226Ra.

Uses of Radon


Radon was used for treating cancer by radiotherapy. Safer treatments are now available.

Abundance & Isotopes

Abundance earth's crust: 4 x10-13 milligrams per kilogram
Abundance solar system:
Cost, pure: $ per 100g
Cost, bulk: $ per 100g

Source:Radon is produced naturally by the radioactive decay of uranium and other elements, such as radium. For example, 222Rn is produced by the decay of radium (226Ra).

Isotopes: Radon has 33 isotopes whose half-lives are known, with mass numbers 196 to 228. None are stable. The most stable isotope is 222Rn, with a half-life of 3.8 days.

Energies

Specific heat capacity: 0.09 J g-1 K-1
Heat of fusion: 2.890 kJ mol-1
1st ionization energy: 1037 kJ mol-1
3rd ionization energy: kJ mol-1
Heat of atomization: 0 kJ mol-1
Heat of vaporization: 16.40 kJ mol-1
2nd ionization energy: kJ mol-1
Electron affinity: kJ mol-1

Oxidation & Electrons

Shells: 2,8,18,32,18,8
Minimum oxidation number: 0
Min. common oxidation no.: 0
Electronegativity (Pauling Scale):
Electron configuration: [Xe] 4f14 5d10 6s2 6p6
Maximum oxidation number: 0
Max. common oxidation no.: 0
Polarizability volume: 5.3 Å3

Reactions & Compounds

Reaction with air: none
Reaction with 15 M HNO3: none
Oxide(s): none
Hydride(s): none
Reaction with 6 M HCl: none
Reaction with 6 M NaOH: none
Chloride(s): none

Radius

Atomic radius: pm
Ionic radius (2+ ion): pm
Ionic radius (2- ion): pm
Ionic radius (1+ ion): pm
Ionic radius (3+ ion): pm
Ionic radius (1- ion): pm

Conductivity

Thermal conductivity: 3.61 W m-1 K-1
Electrical conductivity: S cm-1


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