Difference between revisions of "Argon"
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Most of the volatiles have been deposited in the top layers of the Moon's surface by the solar wind over geologic time. A notable exception to this is Argon. the concentration of Argon in lunar soil is much higher than found in the solar wind, so must come from a different source. Especially, the isotope Argon-40. It is presently believed that the Argon-40 comes from radioactive decay of Potassium and/or Krypton deep within the lunar mantle or core, and that the Argon-40 seeps out to the surface via fissures. This vented Argon enter the [[lunar atmosphere]]; then the Argon is implanted into the [[regolith]] by interactions with ions from the solar wind. | Most of the volatiles have been deposited in the top layers of the Moon's surface by the solar wind over geologic time. A notable exception to this is Argon. the concentration of Argon in lunar soil is much higher than found in the solar wind, so must come from a different source. Especially, the isotope Argon-40. It is presently believed that the Argon-40 comes from radioactive decay of Potassium and/or Krypton deep within the lunar mantle or core, and that the Argon-40 seeps out to the surface via fissures. This vented Argon enter the [[lunar atmosphere]]; then the Argon is implanted into the [[regolith]] by interactions with ions from the solar wind. | ||
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+ | Public domain info obtained from NASA: | ||
+ | |||
+ | Moon Fact Sheet | ||
+ | |||
+ | http://nssdc.gsfc.nasa.gov/planetary/factsheet/moonfact.html | ||
+ | |||
+ | Lunar Atmosphere Estimated Composition (particles per cubic cm): | ||
+ | |||
+ | Helium 4 (4He) - 40,000 | ||
+ | Neon 20 (20Ne) - 40,000 | ||
+ | Hydrogen (H2) - 35,000 | ||
+ | Argon 40 (40Ar) - 30,000 | ||
+ | Neon 22 (22Ne) - 5,000 | ||
+ | Argon 36 (36Ar) - 2,000 | ||
{{Autostub}} | {{Autostub}} |
Revision as of 05:13, 31 August 2007
Argon | |
---|---|
Ar | |
In situ availability: | |
Necessity: | |
Atomic number: | 18 |
Atomic mass: | 39.948 |
group: | 18 |
period: | 3 |
normal phase: | Gas |
series: | Noble gases |
density: | 1.784 g/L |
melting point: | 83.80K, -189.35°C, -308.83°F |
boiling point: | 87.30K, -185.85°C, -302.53°F |
F ← Ne → N/A | |
Cl ← Ar → K | |
Br ← Kr → N/A | |
Atomic radius (pm): | 71 |
Bohr radius (pm): | 71 |
Covalent radius (pm): | 97 |
Van der Waals radius (pm): | 188 |
ionic radius (pm): | - |
1st ion potential (eV): | 15.76 |
Electron Configuration | |
1s2 2s2 2p6 3s2 3p6 | |
Electrons Per Shell | |
2, 8, 8 | |
Electronegativity: | |
Electron Affinity: | Unstable anion |
Oxidation states: | - |
Magnetism: | Nonmagnetic |
Crystal structure: | Face centered cubic |
Argon is a Noble gas in group 18.
It has a Face centered cubic crystalline structure.
This element has 3 stable isotopes: 36, 38, and 40.
Most of the volatiles have been deposited in the top layers of the Moon's surface by the solar wind over geologic time. A notable exception to this is Argon. the concentration of Argon in lunar soil is much higher than found in the solar wind, so must come from a different source. Especially, the isotope Argon-40. It is presently believed that the Argon-40 comes from radioactive decay of Potassium and/or Krypton deep within the lunar mantle or core, and that the Argon-40 seeps out to the surface via fissures. This vented Argon enter the lunar atmosphere; then the Argon is implanted into the regolith by interactions with ions from the solar wind.
Public domain info obtained from NASA:
Moon Fact Sheet
http://nssdc.gsfc.nasa.gov/planetary/factsheet/moonfact.html
Lunar Atmosphere Estimated Composition (particles per cubic cm):
Helium 4 (4He) - 40,000 Neon 20 (20Ne) - 40,000 Hydrogen (H2) - 35,000 Argon 40 (40Ar) - 30,000 Neon 22 (22Ne) - 5,000 Argon 36 (36Ar) - 2,000
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