Neon is a chemical element with symbol Ne and atomic number 10. It is a noble gas. Neon is a colorless, odorless, inert monatomic gas under standard conditions, with about two-thirds the density of air. It was discovered (along with krypton and xenon) in 1898 as one of the three residual rare inert elements remaining in dry air, after nitrogen, oxygen, argon and carbon dioxide were removed. Neon was the second of these three rare gases to be discovered and was immediately recognized as a new element from its bright red emission spectrum. The name neon is derived from the Greek word, νέον, neuter singular form of νέος (neos), meaning new. Neon is chemically inert, and no uncharged neon compounds are known. The compounds of neon currently known include ionic molecules, molecules held together by van der Waals forces and clathrates.
During cosmic nucleogenesis of the elements, large amounts of neon are built up from the alpha-capture fusion process in stars. Although neon is a very common element in the universe and solar system (it is fifth in cosmic abundance after hydrogen, helium, oxygen and carbon), it is rare on Earth. It composes about 18.2 ppm of air by volume (this is about the same as the molecular or mole fraction) and a smaller fraction in Earth's crust. The reason for neon's relative scarcity on Earth and the inner (terrestrial) planets is that neon is highly volatile and forms no compounds to fix it to solids. As a result, it escaped from the planetesimals under the warmth of the newly ignited Sun in the early Solar System. Even the outer atmosphere of Jupiter is somewhat depleted of neon, although for a different reason. It is also lighter than air, causing it to escape even from Earth's atmosphere.
Neon gives a distinct reddish-orange glow when used in low-voltage neon glow lamps, high-voltage discharge tubes and neon advertising signs. The red emission line from neon also causes the well known red light of helium–neon lasers. Neon is used in some plasma tube and refrigerant applications but has few other commercial uses. It is commercially extracted by the fractional distillation of liquid air. Since air is the only source, it is considerably more expensive than helium.
|Appearance||colorless gas exhibiting an orange-red glow when placed in an electric field|
|Standard atomic weight Ar, std(Ne)||20.1797(6)|
|Neon in the periodic table|
|Atomic number (Z)||10|
|Group||group 18 (noble gases)|
|Element category||noble gas|
|Electron configuration||[He] 2s2 2p6|
Electrons per shell
|Phase at STP||gas|
|Melting point||24.56 K (−248.59 °C, −415.46 °F)|
|Boiling point||27.104 K (−246.046 °C, −410.883 °F)|
|Density (at STP)||0.9002 g/L|
|when liquid (at b.p.)||1.207 g/cm3|
|Triple point||24.556 K, 43.37 kPa|
|Critical point||44.4918 K, 2.7686 MPa|
|Heat of fusion||0.335 kJ/mol|
|Heat of vaporization||1.71 kJ/mol|
|Molar heat capacity||20.79 J/(mol·K)|
|Covalent radius||58 pm|
|Van der Waals radius||154 pm|
Spectral lines of neon
|Crystal structure|| face-centered cubic (fcc)|
|Speed of sound||435 m/s (gas, at 0 °C)|
|Thermal conductivity||49.1×10−3 W/(m·K)|
|Magnetic susceptibility||−6.74·10−6 cm3/mol (298 K)|
|Bulk modulus||654 GPa|
|Prediction||William Ramsay (1897)|
|Discovery and first isolation||William Ramsay & Morris Travers (1898)|
|Main isotopes of neon|
Neon was discovered in 1898 by the British chemists Sir William Ramsay (1852–1916) and Morris W. Travers (1872–1961) in London. Neon was discovered when Ramsay chilled a sample of air until it became a liquid, then warmed the liquid and captured the gases as they boiled off. The gases nitrogen, oxygen, and argon had been identified, but the remaining gases were isolated in roughly their order of abundance, in a six-week period beginning at the end of May 1898. First to be identified was krypton. The next, after krypton had been removed, was a gas which gave a brilliant red light under spectroscopic discharge. This gas, identified in June, was named "neon", the Greek analogue of the Latin novum ('new') suggested by Ramsay's son. The characteristic brilliant red-orange color emitted by gaseous neon when excited electrically was noted immediately. Travers later wrote: "the blaze of crimson light from the tube told its own story and was a sight to dwell upon and never forget."
A second gas was also reported along with neon, having approximately the same density as argon but with a different spectrum – Ramsay and Travers named it metargon. However, subsequent spectroscopic analysis revealed it to be argon contaminated with carbon monoxide. Finally, the same team discovered xenon by the same process, in September 1898.
Neon's scarcity precluded its prompt application for lighting along the lines of Moore tubes, which used nitrogen and which were commercialized in the early 1900s. After 1902, Georges Claude's company Air Liquide produced industrial quantities of neon as a byproduct of his air-liquefaction business. In December 1910 Claude demonstrated modern neon lighting based on a sealed tube of neon. Claude tried briefly to sell neon tubes for indoor domestic lighting, due to their intensity, but the market failed because homeowners objected to the color. In 1912, Claude's associate began selling neon discharge tubes as eye-catching advertising signs and was instantly more successful. Neon tubes were introduced to the U.S. in 1923 with two large neon signs bought by a Los Angeles Packard car dealership. The glow and arresting red color made neon advertising completely different from the competition. The intense color and vibrancy of neon equated with American society at the time, suggesting a "century of progress" and transforming cities into sensational new environments filled with radiating advertisements and "electro-graphic architecture".
Neon played a role in the basic understanding of the nature of atoms in 1913, when J. J. Thomson, as part of his exploration into the composition of canal rays, channeled streams of neon ions through a magnetic and an electric field and measured the deflection of the streams with a photographic plate. Thomson observed two separate patches of light on the photographic plate (see image), which suggested two different parabolas of deflection. Thomson eventually concluded that some of the atoms in the neon gas were of higher mass than the rest. Though not understood at the time by Thomson, this was the first discovery of isotopes of stable atoms. Thomson's device was a crude version of the instrument we now term a mass spectrometer.
Neon is the second lightest inert gas. Neon has three stable isotopes: 20Ne (90.48%), 21Ne (0.27%) and 22Ne (9.25%). 21Ne and 22Ne are partly primordial and partly nucleogenic (i.e. made by nuclear reactions of other nuclides with neutrons or other particles in the environment) and their variations in natural abundance are well understood. In contrast, 20Ne (the chief primordial isotope made in stellar nucleosynthesis) is not known to be nucleogenic or radiogenic. The causes of the variation of 20Ne in the Earth have thus been hotly debated.
The principal nuclear reactions generating nucleogenic neon isotopes start from 24Mg and 25Mg, which produce 21Ne and 22Ne respectively, after neutron capture and immediate emission of an alpha particle. The neutrons that produce the reactions are mostly produced by secondary spallation reactions from alpha particles, in turn derived from uranium-series decay chains. The net result yields a trend towards lower 20Ne/22Ne and higher 21Ne/22Ne ratios observed in uranium-rich rocks such as granites. 21Ne may also be produced in a nucleogenic reaction, when 20Ne absorbs a neutron from various natural terrestrial neutron sources.
In addition, isotopic analysis of exposed terrestrial rocks has demonstrated the cosmogenic (cosmic ray) production of 21Ne. This isotope is generated by spallation reactions on magnesium, sodium, silicon, and aluminium. By analyzing all three isotopes, the cosmogenic component can be resolved from magmatic neon and nucleogenic neon. This suggests that neon will be a useful tool in determining cosmic exposure ages of surface rocks and meteorites.
Similar to xenon, neon content observed in samples of volcanic gases is enriched in 20Ne and nucleogenic 21Ne relative to 22Ne content. The neon isotopic content of these mantle-derived samples represents a non-atmospheric source of neon. The 20Ne-enriched components are attributed to exotic primordial rare-gas components in the Earth, possibly representing solar neon. Elevated 20Ne abundances are found in diamonds, further suggesting a solar-neon reservoir in the Earth.
Neon is the second-lightest noble gas, after helium. It glows reddish-orange in a vacuum discharge tube. Also, neon has the narrowest liquid range of any element: from 24.55 K to 27.05 K (−248.45 °C to −245.95 °C, or −415.21 °F to −410.71 °F). It has over 40 times the refrigerating capacity (per unit volume) of liquid helium and three times that of liquid hydrogen. In most applications it is a less expensive refrigerant than helium.
Neon plasma has the most intense light discharge at normal voltages and currents of all the noble gases. The average color of this light to the human eye is red-orange due to many lines in this range; it also contains a strong green line, which is hidden, unless the visual components are dispersed by a spectroscope.
Two quite different kinds of neon lighting are in common use. Neon glow lamps are generally tiny, with most operating between 100 and 250 volts. They have been widely used as power-on indicators and in circuit-testing equipment, but light-emitting diodes (LEDs) now dominate in those applications. These simple neon devices were the forerunners of plasma displays and plasma television screens. Neon signs typically operate at much higher voltages (2–15 kilovolts), and the luminous tubes are commonly meters long. The glass tubing is often formed into shapes and letters for signage, as well as architectural and artistic applications.
Stable isotopes of neon are produced in stars. 20Ne is created in fusing helium and oxygen in the alpha process. This requires temperatures above 100 megakelvins, which are only available in the cores of stars of more than 3 solar masses.
Neon is abundant on a universal scale; it is the fifth most abundant chemical element in the universe by mass, after hydrogen, helium, oxygen, and carbon (see chemical element). Its relative rarity on Earth, like that of helium, is due to its relative lightness, high vapor pressure at very low temperatures, and chemical inertness, all properties which tend to keep it from being trapped in the condensing gas and dust clouds that formed the smaller and warmer solid planets like Earth.
Neon is monatomic, making it lighter than the molecules of diatomic nitrogen and oxygen which form the bulk of Earth's atmosphere; a balloon filled with neon will rise in air, albeit more slowly than a helium balloon.
Neon's abundance in the universe is about 1 part in 750; in the Sun and presumably in the proto-solar system nebula, about 1 part in 600. The Galileo spacecraft atmospheric entry probe found that even in the upper atmosphere of Jupiter, the abundance of neon is reduced (depleted) by about a factor of 10, to a level of 1 part in 6,000 by mass. This may indicate that even the ice-planetesimals which brought neon into Jupiter from the outer solar system, formed in a region which was too warm to retain the neon atmospheric component (abundances of heavier inert gases on Jupiter are several times that found in the Sun).
Neon comprises 1 part in 55,000 in the Earth's atmosphere, or 18.2 ppm by volume (this is about the same as the molecule or mole fraction), or 1 part in 79,000 of air by mass. It comprises a smaller fraction in the crust. It is industrially produced by cryogenic fractional distillation of liquefied air.
Neon is the first p-block noble gas, and the first element with a true octet of electrons. It is inert: as is the case with its lighter analogue, helium, no strongly bound neutral molecules containing neon have been identified. The ions [NeAr]+, [NeH]+, and [HeNe]+ have been observed from optical and mass spectrometric studies. Solid neon clathrate hydrate was produced from water ice and neon gas at pressures 0.35–0.48 GPa and temperatures about −30 °C. Ne atoms are not bonded to water and can freely move through this material. They can be extracted by placing the clathrate into a vacuum chamber for several days, yielding ice XVI, the least dense crystalline form of water.
The familiar Pauling electronegativity scale relies upon chemical bond energies, but such values have obviously not been measured for inert helium and neon. The Allen electronegativity scale, which relies only upon (measurable) atomic energies, identifies neon as the most electronegative element, closely followed by fluorine and helium.
Neon is often used in signs and produces an unmistakable bright reddish-orange light. Although tube lights with other colors are often called "neon", they use different noble gases or varied colors of fluorescent lighting.
Neon is used in vacuum tubes, high-voltage indicators, lightning arresters, wavemeter tubes, television tubes, and helium–neon lasers. Liquefied neon is commercially used as a cryogenic refrigerant in applications not requiring the lower temperature range attainable with more extreme liquid-helium refrigeration.
Neon, as liquid or gas, is relatively expensive – for small quantities, the price of liquid neon can be more than 55 times that of liquid helium. Driving neon's expense is the rarity of neon, which unlike helium, can only be obtained from air.
Plasma displays are closely related to the simple neon lamp.
ARM, previously Advanced RISC Machine, originally Acorn RISC Machine, is a family of reduced instruction set computing (RISC) architectures for computer processors, configured for various environments. Arm Holdings develops the architecture and licenses it to other companies, who design their own products that implement one of those architectures—including systems-on-chips (SoC) and systems-on-modules (SoM) that incorporate memory, interfaces, radios, etc. It also designs cores that implement this instruction set and licenses these designs to a number of companies that incorporate those core designs into their own products.
Processors that have a RISC architecture typically require fewer transistors than those with a complex instruction set computing (CISC) architecture (such as the x86 processors found in most personal computers), which improves cost, power consumption, and heat dissipation. These characteristics are desirable for light, portable, battery-powered devices—including smartphones, laptops and tablet computers, and other embedded systems. For supercomputers, which consume large amounts of electricity, ARM could also be a power-efficient solution.ARM Holdings periodically releases updates to the architecture. Architecture versions ARMv3 to ARMv7 support 32-bit address space (pre-ARMv3 chips, made before ARM Holdings was formed, as used in the Acorn Archimedes, had 26-bit address space) and 32-bit arithmetic; most architectures have 32-bit fixed-length instructions. The Thumb version supports a variable-length instruction set that provides both 32- and 16-bit instructions for improved code density. Some older cores can also provide hardware execution of Java bytecodes. Released in 2011, the ARMv8-A architecture added support for a 64-bit address space and 64-bit arithmetic with its new 32-bit fixed-length instruction set.With over 100 billion ARM processors produced as of 2017, ARM is the most widely used instruction set architecture and the instruction set architecture produced in the largest quantity. Currently, the widely used Cortex cores, older "classic" cores, and specialized SecurCore cores variants are available for each of these to include or exclude optional capabilities.Chrysler Neon
The Plymouth/Dodge/Chrysler Neon is a front-engine, front-wheel drive compact car introduced in January 1994 for model year 1995 by Chrysler's Dodge and Plymouth divisions in two- and four-door bodystyles over two generations.
Marketed in Europe, Mexico, Canada, Japan, Egypt, Australia and South America as a Chrysler, the Neon was offered in multiple versions and configurations over its production life, which ended with model year 2005.
The Neon nameplate was subsequently resurrected in 2016 for the Dodge Neon, a rebadged variant of Fiat Tipo sedan for the Mexican market.Enosis Neon Paralimni FC
Enosis Neon Paralimni Football Club (Greek: Ένωση Νέων Παραλιμνίου, Enosi Neon Paralimniou, "Youth Union of Paralimni") is a Cypriot football team from Paralimni. Currently playing in the first division, it holds home games at the Paralimni Municipal Stadium "Tasos Marcou", which holds 5,800 people.Isotopes of neon
Neon (10Ne) possesses three stable isotopes, 20Ne, 21Ne, and 22Ne. In addition, 16 radioactive isotopes have been discovered ranging from 16Ne to 34Ne, all short-lived. The longest-lived is 24Ne with a half-life of 3.38 minutes. All others are under a minute, most under a second. The least stable is 16Ne with a half-life of 9×10−21 s. See isotopes of carbon for notes about the measurement.KDE neon
KDE neon is a set of software repositories for Ubuntu long-term support (LTS) releases with latest 64-bit version of KDE desktop and applications. It is also the name given to a Ubuntu LTS-based Linux distribution that utilizes said repositories. It aims to provide the users with rapidly updated Qt and KDE software, while updating the rest of the OS components from the Ubuntu repositories at the normal pace. It comes in user and developer editions.
The KDE neon Linux distribution is focused on the development of KDE. The emphasis is on bleeding edge software packages sourced directly from KDE and offers programmers early access to new features, but potentially at the cost of greater susceptibility to software bugs.KDE neon announced in January 2017 that the distribution switching its installer from Ubiquity to Calamares due to Ubiquity "not having some features".In February 2018, KDE neon developers removed the LTS Editions from the downloads page, but kept these editions in the download mirrors because of "lots of people asking which edition to use and what the difference is."In May 2018, KDE started changing KDE neon from being based on Ubuntu 16.04 to Ubuntu 18.04. KDE neon preview images, based on Ubuntu 18.04, became available in August 2018.List of Neon Genesis Evangelion characters
This is a list of characters in the anime Neon Genesis Evangelion and the movies Evangelion: Death & Rebirth, The End of Evangelion and the Rebuild of Evangelion tetralogy. The characters were designed by Yoshiyuki Sadamoto.Neon-burning process
The neon-burning process (nuclear decay) is a set of nuclear fusion reactions that take place in massive stars (at least 8 Solar masses). Neon burning requires high temperatures and densities (around 1.2×109 K or 100 KeV and 4×109 kg/m3).
At such high temperatures photodisintegration becomes a significant effect, so some neon nuclei decompose, releasing alpha particles:
where the neutron consumed in the first step is regenerated in the second.
Neon burning takes place after carbon burning has consumed all carbon in the core and built up a new oxygen-neon-sodium-magnesium core. The core ceases producing fusion energy and contracts. This contraction increases density and temperature up to the ignition point of neon burning. The increased temperature around the core allows carbon to burn in a shell, and there will be shells burning helium and hydrogen outside.
During neon burning, oxygen and magnesium accumulate in the central core while neon is consumed. After a few years the star consumes all its neon and the core ceases producing fusion energy and contracts. Again, gravitational pressure takes over and compresses the central core, increasing its density and temperature until the oxygen-burning process can start.Neon Bible
Neon Bible is the second studio album by Canadian indie rock band Arcade Fire. It was first released on March 5, 2007 in Europe and a day later in North America by Merge Records. Originally announced on December 16, 2006 through the band's website, the majority of the album was recorded at a church the band bought and renovated in Farnham, Quebec. The album is the first to feature drummer Jeremy Gara, and the first to include violinist Sarah Neufeld among the band's core line-up.
Neon Bible became Arcade Fire's highest-charting album at the time, debuting on the Billboard 200 at number two, selling 92,000 copies in its first week and more than 400,000 to date. Being released within a month of similarly successful releases by The Shins (Wincing the Night Away) and Modest Mouse (We Were Dead Before the Ship Even Sank), Neon Bible was cited as an example of the popularization of indie rock. Critics gave the self-produced Neon Bible mostly favorable reviews, although with division over the album's sound. Publications like NME and IGN praised the album for its grandiose nature, while Rolling Stone and Uncut said that it resulted in a distant and overblown sound.Neon Genesis Evangelion
Neon Genesis Evangelion (Japanese: 新世紀エヴァンゲリオン, Hepburn: Shinseiki Evangerion, literally "The Gospel of the New Century") is a Japanese mecha anime television series produced by Gainax and Tatsunoko Production, directed by Hideaki Anno and broadcast on TV Tokyo from October 1995 to March 1996. The cast included Megumi Ogata as Shinji Ikari, Megumi Hayashibara as Rei Ayanami, and Yūko Miyamura as Asuka Langley Soryu. The music was composed by Shirō Sagisu.
Evangelion is set fifteen years after a worldwide cataclysm, particularly in the futuristic fortified city of Tokyo-3. The protagonist is Shinji, a teenage boy who was recruited by his father to the shadowy organization Nerv to pilot a giant bio-machine mecha called an "Evangelion" into combat with alien beings called "Angels". The series explores the experiences and emotions of Evangelion pilots and members of Nerv as they try to prevent any and all of the Angels from causing another cataclysm, and as they deal with the quest of finding out the real truth behind events and organizational moves. The series features imagery derived from Kabbalah, Christianity, and Judaism.
Neon Genesis Evangelion received critical acclaim, and garnered controversy. Particularly controversial were the last two episodes of the show, leading the team behind the series to produce the original intended version of the ending in the 1997 film The End of Evangelion. Regarded as a deconstruction of the mecha genre, the original TV series led to a rebirth of the anime industry and has become a cultural icon. Film, manga, home video, and other products in the Evangelion franchise have achieved record sales in Japanese markets and strong sales in overseas markets, with related goods selling over ¥150 billion by 2007 and Evangelion pachinko machines selling ¥700 billion by 2015.Neon Trees
Neon Trees are an American rock band from Provo, Utah. Known for their energetic live performances, the band received nationwide exposure in late 2008 when they opened several North American tour dates for the band The Killers. Not long after, the band was signed by Mercury Records and released their first studio album, Habits, in 2010. Their first single, "Animal", climbed to No. 13 on the Billboard Hot 100 and No. 1 on the Alternative Songs chart.Neon lamp
A neon lamp (also neon glow lamp) is a miniature gas discharge lamp. The lamp typically consists of a small glass capsule that contains a mixture of neon and other gases at a low pressure and two electrodes (an anode and a cathode). When sufficient voltage is applied and sufficient current is supplied between the electrodes, the lamp produces an orange glow discharge. The glowing portion in the lamp is a thin region near the cathode; the larger and much longer neon signs are also glow discharges, but they use the positive column which is not present in the ordinary neon lamp. Neon glow lamps are widely used as indicator lamps in the displays of electronic instruments and appliances.Neon lighting
Neon lighting consists of brightly glowing, electrified glass tubes or bulbs that contain rarefied neon or other gases. Neon lights are a type of cold cathode gas-discharge light. A neon tube is a sealed glass tube with a metal electrode at each end, filled with one of a number of gases at low pressure. A high potential of several thousand volts applied to the electrodes ionizes the gas in the tube, causing it to emit colored light. The color of the light depends on the gas in the tube. Neon lights were named for neon, a noble gas which gives off a popular orange light, but other gases and chemicals are used to produce other colors, such as hydrogen (red), helium (yellow), carbon dioxide (white), and mercury (blue). Neon tubes can be fabricated in curving artistic shapes, to form letters or pictures. They are mainly used to make dramatic, multicolored glowing signage for advertising, called neon signs, which were popular from the 1920s to the 1950s.
The term can also refer to the miniature neon glow lamp, developed in 1917, about seven years after neon tube lighting. While neon tube lights are typically meters long, the neon lamps can be less than one centimeter in length and glow much more dimly than the tube lights. They are still in use as small indicator lights. Through the 1970s, neon glow lamps were widely used for numerical displays in electronics, for small decorative lamps, and as signal processing devices in circuity. While these lamps are now antiques, the technology of the neon glow lamp developed into contemporary plasma displays and televisions.Neon was discovered in 1898 by the British scientists William Ramsay and Morris W. Travers. After obtaining pure neon from the atmosphere, they explored its properties using an "electrical gas-discharge" tube that was similar to the tubes used for neon signs today. Georges Claude, a French engineer and inventor, presented neon tube lighting in essentially its modern form at the Paris Motor Show from December 3–18, 1910. Claude, sometimes called "the Edison of France", had a near monopoly on the new technology, which became very popular for signage and displays in the period 1920-1940. Neon lighting was an important cultural phenomenon in the United States in that era; by 1940, the downtowns of nearly every city in the US were bright with neon signage, and Times Square in New York City was known worldwide for its neon extravagances. There were 2000 shops nationwide designing and fabricating neon signs. The popularity, intricacy, and scale of neon signage for advertising declined in the U.S. following the Second World War (1939–1945), but development continued vigorously in Japan, Iran, and some other countries. In recent decades architects and artists, in addition to sign designers, have again adopted neon tube lighting as a component in their works.Neon lighting is closely related to fluorescent lighting, which developed about 25 years after neon tube lighting. In fluorescent lights, the light emitted by rarefied gases within a tube is used exclusively to excite fluorescent materials that coat the tube, which then shine with their own colors that become the tube's visible, usually white, glow. Fluorescent coatings and glasses are also an option for neon tube lighting, but are usually selected to obtain bright colors.Neon sign
In the signage industry, neon signs are electric signs lighted by long luminous gas-discharge tubes that contain rarefied neon or other gases. They are the most common use for neon lighting, which was first demonstrated in a modern form in December 1910 by Georges Claude at the Paris Motor Show. While they are used worldwide, neon signs were popular in the United States from about 1920–1960. The installations in Times Square, many originally designed by Douglas Leigh, were famed, and there were nearly 2,000 small shops producing neon signs by 1940. In addition to signage, neon lighting is used frequently by artists and architects, and (in a modified form) in plasma display panels and televisions. The signage industry has declined in the past several decades, and cities are now concerned with preserving and restoring their antique neon signs.Noble gas
The noble gases (historically also the inert gases; sometimes referred to as aerogens) make up a group of chemical elements with similar properties; under standard conditions, they are all odorless, colorless, monatomic gases with very low chemical reactivity. The six noble gases that occur naturally are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and the radioactive radon (Rn). These elements are all nonmetals. Oganesson (Og) is variously predicted to be a noble gas as well or to break the trend due to relativistic effects; its chemistry has not yet been investigated.
For the first six periods of the periodic table, the noble gases are exactly the members of group 18. Noble gases are typically highly unreactive except when under particular extreme conditions. The inertness of noble gases makes them very suitable in applications where reactions are not wanted. For example, argon is used in incandescent lamps to prevent the hot tungsten filament from oxidizing; also, helium is used in breathing gas by deep-sea divers to prevent oxygen, nitrogen and carbon dioxide (hypercapnia) toxicity.
The properties of the noble gases can be well explained by modern theories of atomic structure: their outer shell of valence electrons is considered to be "full", giving them little tendency to participate in chemical reactions, and it has been possible to prepare only a few hundred noble gas compounds. The melting and boiling points for a given noble gas are close together, differing by less than 10 °C (18 °F); that is, they are liquids over only a small temperature range.
Neon, argon, krypton, and xenon are obtained from air in an air separation unit using the methods of liquefaction of gases and fractional distillation. Helium is sourced from natural gas fields that have high concentrations of helium in the natural gas, using cryogenic gas separation techniques, and radon is usually isolated from the radioactive decay of dissolved radium, thorium, or uranium compounds (since those compounds give off alpha particles). Noble gases have several important applications in industries such as lighting, welding, and space exploration. A helium-oxygen breathing gas is often used by deep-sea divers at depths of seawater over 55 m (180 ft) to keep the diver from experiencing oxygen toxemia, the lethal effect of high-pressure oxygen, nitrogen narcosis, the distracting narcotic effect of the nitrogen in air beyond this partial-pressure threshold, and carbon dioxide poisoning (hypercapnia), the panic-inducing effect of excessive carbon dioxide in the bloodstream. After the risks caused by the flammability of hydrogen became apparent, it was replaced with helium in blimps and balloons.Opera (web browser)
Opera is a web browser for Windows, macOS, and Linux operating systems . Opera Ltd. is publicly listed on the NASDAQ stock exchange , with majority ownership and control belongs to Yahui Zhou, creator of Beijing Kunlun Tech. Opera is a Chromium-based browser using the Blink layout engine. It differentiates itself with a distinct user interface and other features.
Opera was conceived at Telenor as a research project in 1994 and was bought by Opera Software in 1995. It was commercial software for the first ten years and had its own proprietary Presto layout engine. The Presto versions of Opera received many awards, but Presto development ended after the big transition to Chromium in 2013.
There are also three mobile versions called Opera Mobile, Opera Touch and Opera Mini.Steve Aoki
Steven Hiroyuki Aoki (; born November 30, 1977) is an American electro house musician, record producer, DJ, and music executive. In 2012, Pollstar designated Aoki as the highest grossing dance artist in North America from tours. He has collaborated with artists such as will.i.am, Afrojack, LMFAO, Linkin Park, Iggy Azalea, Lil Jon, blink-182, Laidback Luke, BTS, Louis Tomlinson, Rise Against, Vini Vici, Lauren Jauregui, and Fall Out Boy and is known for his remixes of artists such as Kid Cudi. Aoki has released several Billboard-charting studio albums as well, notably Wonderland, which was nominated for Grammy Award for Best Dance/Electronica Album in 2013. He is the founder of the Steve Aoki Charitable Fund, which raises money for global humanitarian relief organizations.Test light
A test light, test lamp, voltage tester, or mains tester is a piece of electronic test equipment used to determine the presence of electricity in a piece of equipment under test. A test light is simpler and less costly than a measuring instrument such as a multimeter, and often suffices for checking for the presence of voltage on a conductor. Properly designed test lights include features to protect the user from accidental electric shock. Non-contact test lights can detect voltage on insulated conductors.The End of Evangelion
The End of Evangelion (新世紀エヴァンゲリオン劇場版 Air (エア)/まごころを、君に, Shin Seiki Evangerion Gekijō-ban: Ea/Magokoro o, Kimi ni) is a 1997 Japanese animated science fiction film written and directed by Hideaki Anno and animated by Production I.G. It serves as an alternative ending to the Neon Genesis Evangelion television series, in which teenage Shinji Ikari pilots Evangelion Unit 01, one of several giant cyborgs designed to fight hostile supernatural entities called Angels.
Though it won awards including the 1997 Animage Anime Grand Prix, The End of Evangelion initially received mixed reviews. A 2014 Time Out poll of filmmakers voted The End of Evangelion one of the 100 best animated films of all time.