helium(redirected from Two fluid model for helium)
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n. Symbol He
A colorless, odorless inert gaseous element occurring in natural gas and with radioactive ores. It is used as a component of artificial atmospheres and laser media, as a refrigerant, as a lifting gas for balloons, and as a superfluid in cryogenic research. Atomic number 2; atomic weight 4.0026; boiling point -268.9°C; density at 0°C 0.1785 gram per liter. See Periodic Table.
(Elements & Compounds) a very light nonflammable colourless odourless element that is an inert gas, occurring in certain natural gases: used in balloons and in cryogenic research. Symbol: He; atomic no: 2; atomic wt: 4.002602; density: 0.1785 kg/m3; at normal pressures it is liquid down to absolute zero; melting pt: below –272.2°C; boiling pt: –268.90°C. See also alpha particle
[C19: New Latin, from helio- + -ium; named from its having first been detected in the solar spectrum]
he•li•um(ˈhi li əm)
an inert, gaseous element present in the sun's atmosphere and in natural gas, used as a substitute for flammable gases in dirigibles. Symbol: He; at. wt.: 4.0026; at. no.: 2; density: 0.1785 g/l at 0°C and 760 mm pressure.
[1872; < Greek hḗli(os) the sun + -ium2]
Symbol He A very lightweight, colorless, odorless element that is a noble gas and occurs in natural gas, in radioactive ores, and in small amounts in the atmosphere. It has the lowest boiling point of any substance and is the second most abundant element in the universe. Helium is used to provide lift for balloons and blimps and to create artificial air that will not chemically react. Atomic number 2. See Periodic Table.
Word History A lot of elements are named after the place they were first discovered—even if that place is 93 million miles away, as is the case with the element helium. In 1868 astronomers were studying a solar eclipse with a spectroscope, an instrument that breaks up light into a spectrum. When an element is heated hot enough to glow, the light emitted will produce a unique spectrum (pattern of lines) when refracted through a prism. The astronomers noticed that the spectrum of the sun's corona, which is only visible during an eclipse, contained some lines produced by an unknown element. The element was then named helium, from helios, the Greek word for "sun." We now know that helium is produced abundantly by the nuclear fusion in all stars, and is also found in smaller amounts on Earth. The Greek word helios gives us many other words pertaining to the sun, such as heliocentric and perihelion.
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|Noun||1.||helium - a very light colorless element that is one of the six inert gasses; the most difficult gas to liquefy; occurs in economically extractable amounts in certain natural gases (as those found in Texas and Kansas)|
chemical element, element - any of the more than 100 known substances (of which 92 occur naturally) that cannot be separated into simpler substances and that singly or in combination constitute all matter
helium[ˈhiːlɪəm] N → helio m
n → Helium nt
helium[ˈhiːlɪəm] n → elio
an element, a very light gas which does not burn and which is used eg in balloons. helium هيليوم хелий hélio hélium das Helium helium ήλιοhelio heelium گازهليوم helium hélium הֶליוּם हीलियम, एक गैस helij hélium helium helíum elio ヘリウム 헬륨 helis hēlijs helium heliumheliumhel هېليوم ، د نجيبه غازاتو له جملى څخه يو ډول سپك غاز دش hélio heliu гелий hélium helij helijum helium ก๊าซเฉื่อยชนิดหนึ่งไม่มีสี ไม่มีกลิ่น มีสัญลักษณ์คือ He helyum 氦，氦氣 гелій ایک بے رنگ ہلکی گیس جو قدرتی معدنی گیس کے ساتھ ملی جلی ہوتی ہے khí hêli 氦
n. helio, elemento gaseoso inerte empleado en tratamientos respiratorios y en cámaras de descompresión para facilitar el aumento o disminución de la presión del aire.