Neon Element Information
Neon (Ne), chemical element, inert gas, or noble gas of Group 18 of the periodic table discovered through its physical properties like electromagnetic spectrum and uses widely in fluorescent lamps. Colorless, odorless, tasteless, monoatomic gas, neon occurs to the extent of 18 ppm by volume in dry air and 5 × 10-5 ppm by weight in igneous rocks. The name of the lighter gas, neon derived from the Greek latter neos meaning new. In solid-state, it forms a face-centered cubic crystal lattice.
The inert gas, neon has the chemical symbol Ne, atomic number 10, atomic weight 20.1797, melting point -248.59 °C, boiling point -246.05 °C, density at 1 atm and 0°C 0.89990 gm/liter electron configuration 1s2 2s2 2p6, and heat capacity ratio (Cp/Cv) close to 1.66. Due to filled valence orbital, the oxidation number or state is zero.
History and Occurrence
English natural philosopher and scientist Henry Candavis in 1785 observed that the small sample of air in the atmosphere contains a small volume of gas (1/120 part) even after repeated sparking with excess oxygen. In 1898, British chemists Sir William Ramsay and Morris W. Travers discovered three new elements like neon, krypton, and xenon from the Greek words new, hidden, and strange by low-temperature distillation of liquid air.
Neon is present to the extent of 18 ppm by volume in dry air and 7 × 10-5 ppm by weight in igneous rocks. Like other noble gases (helium, Argon, krypton), neon is mainly obtained as by-products of liquefaction of air. The rare gases can also be fractionated effectively by their preferential adsorption on charcoal at preferred temperatures. At -180 °C charcoal adsorbed argon, krypton, xenon, and radon. Worming the charcoal to -80 °C produced almost pure argon. After the adsorption of argon and heavier rare gases, the lighter neon and helium adsorbed at -225 °C. It has four stable isotopes, 20Ne (90.92 percent), 21Ne (0.26 percent), 23Ne (8.82 percent).
Chemistry of Neon
Neon is the second-lightest noble gas after helium contains completes valence s and p-subshells to make a very stable configuration. The energy required for the promotion of an electron to the next vacant orbitals is quite large. The fact suggests that the covalent bonding of the gas very unfavorable. The formation of ionic compounds by chemical bonding with fluorine is unlikely due to high positive entropy and free energy for the formation of ionic compounds. Therefore, No stable chemical compounds of neon have been observed and the molecule of the element consists of single atoms.
Solid clathrate hydrate was produced from water ice and neon gas at high pressures and −30 °C temperature. The clathrate cannot be called a true compound since it bounded through hydrogen bonding and noble gas molecules freely move through the materials. The gas is liberated when heating. The ionization energy is highest for all noble gases of the periodic table but they do decrease down the group. The facts indicate that if the noble gases show any reactivity, they are present at the lower position of the group.
Properties and Uses of Neon
Neon is widely used in electronics for filling photoelectric cells, voltage stabilizers, vacuum tubes, high voltage indicators, wavemeter tubes, television tubes, helium-neon laser, and similar instruments. The so-called neon lights or bright reddish-orange light in advertisements contains a mixture of noble gases uses in the various colors of fluorescent light. It is a non-conductor of electricity but under low pressure and high voltage, it starts conduction. Under these conditions, ionization of atoms occurs. The exited ion while returning to its ground state emits a characteristics reddish-orange light which is used in conduction lams or signs tables. Liquid neon is used as a cryogenic refrigerant for the refrigeration of helium gas molecules. It cannot be used to attaining lower temperatures like liquid nitrogen and helium due to the high price of neon or expensive than the other liquefied substances.