- an inert, gaseous element present in the sun's atmosphere and in natural gas, and also occurring as a radioactive decomposition product, used as a substitute for flammable gases in dirigible balloons. Symbol: He; atomic weight: 4.0026; atomic number: 2; density: 0.1785 g/l at 0°C and 760 mm pressure.
Origin of helium
- colorless liquid helium existing below its boiling point of 4.2 K and above the lambda point of 2.186 K.
- liquid helium existing as a superfluid below the lambda point of 2.186 K, having very low viscosity and very high thermal conductivity.
Examples from the Web for helium
She added in the high-pitched, over-enunciated voice, like she was alternating between sucking on helium and a bong.SNL’s Kim Kardashian Konundrum: Why Nasim Pedrad’s Exit Hurts So Much
September 26, 2014
After he inhaled sulfur hexafluoride, a compound that acts like helium, his voice got very deep.The Anger Over ‘Tranny,’ From Neil Patrick Harris to RuPaul to Dan Savage
January 30, 2012
As for Hydorn, she says that if she herself hits that low spot, she may one day use the helium hood, too.The 91-Year-Old Woman Selling $60 Suicide Kits
April 27, 2011
And once, Olivia says, “we got balloons full of helium with messages to him and we let them go at night.”'I Don't Have a Dad'
Barbara Kantrowitz, Elspeth Reeve
September 11, 2009
He thought he could send Man to the stars on a string of helium nuclei.Teething Ring
There was only one thing to do, there being only one other gas comparable in lightness to helium.Bread Overhead
Fritz Reuter Leiber
The helium line of the latter had never been noticed to be double.The Story of the Heavens
Robert Stawell Ball
The brain is a physical thing—a bunch of cryotrons in a helium bath.
It was easier to cool the helium bath of the brain if it only had to be lowered 175 degrees or so.
- 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°CSee also alpha particle
Word Origin and History for helium
1868, coined from Greek helios "sun" (see sol), because the element was detected in the solar spectrum during the eclipse of Aug. 18, 1868, by English astronomer Sir Joseph N. Lockyer (1836-1920) and English chemist Sir Edward Frankland (1825-1899). It was not actually obtained until 1895; it was assumed before that to be an alkali metal, hence the ending in -ium.
- An inert gaseous element used in liquid form as a cryogen and as a substitute for nitrogen in artificial breathing mixtures for deep-sea diving and workers in high-pressure conditions. Atomic number 2.
- A very lightweight, colorless, odorless element in the noble gas group. Helium 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 react chemically. Atomic number 2; atomic weight 4.0026; boiling point -268.9°C; density at 0°C 0.1785 gram per liter. See Periodic Table.
Word History: The second most abundant element in the universe after hydrogen, Helium (symbol He) is a colorless, odorless, nonmetallic gas that is produced abundantly by the nuclear fusion in all stars and is found in smaller amounts on Earth. It was discovered by the British scientist-and founding editor of the journal Nature-Joseph Norman Lockyer in 1868, while he was studying a solar eclipse with a spectroscope, an instrument that breaks light up into a spectrum. If an element is heated up enough to glow, the emitted light produces a unique spectrum when refracted through a prism. Lockyer noticed that the spectrum of the Sun's corona, which is visible only during a solar eclipse, contained lines produced by an unknown element. He named the element helium from helios, the Greek word for sun. Helios gives us many other words pertaining to the Sun, such as heliocentric and perihelion.