| Neon - Ne
CAS: 7440-01-9 Description: Colorless, odorless, tasteless gas Classification: Noble Gas Date of Discovery: 1898 Discoverer: Sir William Ramsay Name Origin: Greek neos, "new" |
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Atomic Number: 10
Number of Neutrons: 10 Atomic Mass: 20.1797(6) amu Melting Point: -248.5938 °C Boiling Point: -246.08 °C Density (0 °C, 1 atm): 0.89990 g/cm3 liquid at b.p. - 1.207 g/cm3 Atomic volume: 16.7 cm3/mol Electrical resistivity: 0.630 10-6/cm 
Thermal conductivity: 0.000493 W/cmK Enthalpy of atomization: Enthalpy of vaporization: 1.7326 kJ/mol Enthalpy of fusion: 0.3317 kJ/mol Specific heat capacity: 0.904 J/gK |
Energy levels: 2-8
Electron configuration: [He]2s22p6 Crystal Structure: Cubic face centered Atomic radius: 0.51 Å Covalent radius: 0.71 Å Oxidation States: usually 0 Electronegativity, Pauling: Electron affinity: not stable First ionization energy: 21.564 eV 2nd ionization energy: 40.962 eV 3rd ionization energy: 63.45 eV Polarizability: 0.3956 10-24cm3 |
| Isotope | Natural Abundance | Atomic Mass | Half-life | Decay Mode | Spin |
| 16Ne | 16.02575 | 4 x 10-21 s | 2p | ||
| 17Ne | 17.01770 | 109 ms |  +, p |
1/2- | |
| 18Ne | 18.005710 | 1.67 s | + |
0+ | |
| 19Ne | 19.001880 | 17.22 s | - |
1/2+ | |
| 20Ne | 90.48(3) | 19.99244018 | Stable | 0+ | |
| 21Ne | 0.27(1) | 20.9938467 | Stable | 3/2+ | |
| 22Ne | 9.25(3) | 21.9913855 | Stable | 0+ | |
| 23Ne | 22.9944673 | 37.2 s | - |
5/2+ | |
| 24Ne | 23.99362 | 3.38 m | - |
0+ | |
| 25Ne | 24.99779 | 0.61 s | - |
1/2+ | |
| 26Ne | 26.00046 | 197 ms | - |
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| 27Ne | 27.0076 | 32 ms | -, n |
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| 28Ne | 28.0121 | 17 ms | -, n |
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| 29Ne | 29.0194 | 0.2 s | - |
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Discovered by Ramsay and Travers in 1898. Neon is a rare gaseous element present in the atmosphere to the extent of 1 part in 65,000 of air. It is obtained by liquefaction of air and separated from the other gases by fractional distillation. Natural neon is a mixture of three isotopes. Six other unstable isotopes are known. It is very inert element; however, it is said to form a compound with fluorine. It is still questionable if true compounds of neon exist, but evidence is mounting in favor of their existence.
The following ions are known from optical and mass spectrometric studies: Ne+, (NeAr)+, (NeH)+, and (HeNe+). Neon also forms an unstable hydrate. In a vacuum discharge tube, neon glows reddish orange. Of all the rare gases, the discharge of neon is the most intense at ordinary voltages and currents. Neon is used in making the common neon advertising signs, which accounts for its largest
use. It is also used to make high-voltage indicators, lightning arrestors, wave meter tubes, and TV tubes. Neon and helium are used in making gas lasers. Liquid neon is now commercially available and is finding important application as an economical cryogenic refrigerant. It has over 40 times more refrigerating capacity per unit volume than liquid helium and more than three times that of liquid hydrogen. It is compact, inert, and is less expensive than helium when it meets refrigeration requirements.
LINKS: Auroral Displays Neon and fluorescent lights explained Neon Physical Constants Neon Signs Sir Joseph John Thomson Spectra of Neon Gas Discharge Return
Sources for the information on this website include: Lide, David R., ed. CRC Handbook of Chemistry and Physics, 78th Ed., 1997-1998. |
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