Neon is a rare element, making up only 0.001% of our atmosphere. Part of this percentage was lodged in the rocks of the Earth when the planet was formed, and was released into the air by volcanic eruptions. Pure neon is a transparent gas, which is extracted by cooling the air to a temperature of -189.34 °C (-189.34 °F). This element can be mixed with helium to create research lasers. However, it is more commonly used in lighting, such as in illuminated signs or as bright warning beacons on airport runways.
Summary of properties (Ne)
| Atomic weight | 20.1797(6) |
| Discoverer (year) | Ramsay, William & Travers, Morris (1898) |
| Natural form | gas |
| Electron configuration | [He] 2s2 2p6 |
| Melting point (ºC) | -249 |
| Boiling point (ºC) | -246 |
| Abundance in earth's crust (ppm) | 0.005 |
| Isotope (abundance) | 20Ne (90.48), 21Ne (0.27), 22Ne (9.25) |
| Density g/cm3 | 0.9 |
| Van der Waals radius (pm) | 154 |
| Covalent radius (pm) | 62 |
| Electronegativity (Pauling) | |
| Vaporization enthalpy (kJ/mol) | 1.71 |
| Enthalpy of fusion (kJ/mol) | 0.33 |
| Specific heat capacity (J/g·K) at 25ºC and 1 atm | 1.03 |
| Thermal conductivity (W/cm·K) at 25ºC and 1 atm | <0.001 |
| Oxidation state | 0 |
| Electron affinity (eV) | unstable ion |
| 1st Ionization potential (eV) | 21.5645 |
