Helium Sentence Examples
Helium is present in the atmosphere, of which it constitutes four parts in a million.
It dissolves readily in strong nitric acid, and the helium contained is thus liberated.
The conclusion which was originally drawn from this fact that helium is a mixture of two gases has not been confirmed, as one of the spectra of oxygen is similarly constituted.
Much the best practical source of helium is thorianite, a mineral imported from Ceylon for the manufacture of thoria.
A part of the helium contained in minerals can be extracted by heat or by grinding.Advertisement
In the visual spectrum there are four hydrogen lines and one helium line in which the actual shapes may be examined.
In 1894 he was associated with Lord Rayleigh in the discovery of argon, announced at that year's meeting of the British Association in Oxford, and in the following year he found in certain rare minerals such as cleveite the gas helium which till that time had only been known on spectroscopic evidence as existing in the sun.
With Regard To The Scale Of Temperature, There Is Very General Agreement That The Absolute Scale As Realized By The Hydrogen Or Helium Thermometer Should Be Adopted As The Ultimate Standard Of Reference.
At low temperatures, on the other hand, they find, using an initial pressure of 'coo mm., that the temperatures on the helium scale are measurably higher than on the hydrogen scale, owing to the more perfectly gaseous condition of helium.
This Appears To Be Actually The Case For Monatomic Gases Such As Mercury Vapour (Kundt And Warburg, 1876), Argon And Helium (Ramsay, 1896).Advertisement
Thus at high temperatures a helium thermometer is of no special advantage.
Dorn 5 has found the Doppler effect with a number of lines of helium, which contain representatives of the trunk series as well as of the two branch series.
The former are often called " Orion " stars, as all the brighter stars in that constellation with the exception of Betelgeux belong to the helium type.
It is virtually identical with a group known as the " yellow stars," of which the most prominent examples are Capella, Pollux and Arcturus; this is not the most numerous group, however; more than one half of all the stars whose spectra are known belong to a simpler type in which the metallic lines are faint or absent, excepting hydrogen and sometimes helium, which declare themselves with increased prominence.
Strutt has suggested that helium in hot springs may be derived from the disintegration of common rocks at great depths.Advertisement
Helium alone refuses to be absorbed, and it can be pumped off from the charcoal in a state of absolute purity.
Turning to the study of radioactivity, he noticed its association with the minerals which yield helium, and in support of the hypothesis that that gas is a disintegration-product of radium he proved in 1903 that it is continuously formed by the latter substance in quantities sufficiently great to be directly recognizable in the spectroscope.
In order to get rid of hydrogen, some oxygen is added to the helium, and the mixture exploded by an electric spark.
In the absence of liquid air the helium must be purified by the methods employed for argon (q.v.).
Properties.--All attempts to make helium enter into stable chemical union have hitherto proved unsuccessful.Advertisement
The refractivity of helium is 0.1238 (air =1).
Helium mass spectrometer leak test to detect even the tiniest of leaks.
About the beginning of the 10th century, however, the view was promulgated that the spontaneous production of helium from radium may be an instance of the transformation of one element into another.
It is found that mercury vapour, helium, argon and its associates (neon, krypton, &c.) have the value 1.67; hence we conclude that these gases exist as monatomic molecules.
Paschen 6 has further extended the method and added a number of infra-red lines to the spectra of helium, argon, oxygen and other elements.Advertisement
Travers have obtained evidence of the existence in the atmosphere of three new gases, besides helium, to which have been assigned the names of neon, krypton and xenon.
Helium stars are generally considered to be the hottest and most luminous (in proportion to size) of all the stars.
The group consisting of five stars of Ursa Major together with Sirius has already been alluded to; another very marked group of 16 stars in Perseus, all of the Helium type of spectrum, form a similar association.
Thus we see that the effect of limiting the magnitude to 3.5 is that the hydrogen stars are now practically all within the sphere SP, and it is only the helium stars, whose absolute luminosity is still greater, that are more widely distributed.
In the higher chromosphere on occasions metallic gases are carried up to such a level that without an eclipse a bright line spectrum of many elements may be seen, but it is always possible to see those of hydrogen and helium, and by opening the slit of the spectroscope so as to weaken still further the continuous spectrum from the photosphere (now a mere reflection) the actual forms of the gaseous structures called prominences round the sun's rim may be seen.
The helium formations do not reach the sun's limb, and it is another puzzling detail that the spectrum of the disk shows no absorption line of anything like an intensity to correspond with the emission line of helium in the chromosphere.
As more helium is accreted, the process repeats itself until all the matter from the companion star is used up.
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Early in star development hydrogen is utilized to manufacture the element helium.
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In brief, because the helium leaks out, they shrink, and become heavier than the volume of air they displace.
Helium is next with two protons, and with three protons we have lithium, and so on.
In the process of fusing hydrogen to form helium, the nuclear reactions also produce elementary particles called neutrinos.
Helium in the Sun Helium in the sun is generally believed to be formed by nuclear fusion.
Familiarity with what is meant by antiparticles, quarks, leptons, hadrons, beta decay, helium nucleosynthesis.
The alpha particle is a helium nucleus - one of the products of a nuclear fission.
Helium pressurized rocket propellant and rocket fuel provides takeoff and thruster power.
In many areas, conventional helium scattering has been limited by the energy resolution with which such measurements can be made.
Helium is contained almost universally in the gases which bubble up with the water of thermal springs.
Travers has suggested that it may explain the liberation of helium from minerals by heat, the gas being enabled to permeate the siliceous materials in which it is enclosed.
The spectrum of helium as observed in a discharge tube is distinguished by a moderate number of brilliant lines, distributed over the whole visual spectrum.
The first, made by Sir William Ramsay in 1896, was that the mineral evolved a peculiar gas when treated with sulphuric acid; this gas, helium (q.v.), proved to be identical with a constituent of the sun's atmosphere, detected as early as 1868 by Sir Norman Lockyer during a spectroscopic examination of the sun's chromosphere.
It is remarkable as always containing helium and radioactive elements (see Radioactivity).
Some authorities, however, consider the Antarian (Type III.) stars to be in a very early stage of development and to precede the helium stars in the order of evolution; in that case they are in the stage when the temperature is still rising.
With H E Hall, he made the experimental discovery of quantized vortices in superfluid helium.
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You can even purchase a couple of helium tanks for about $20 each and fill them up yourself.
A mom who shops at Gymboree commented on Helium that she is able to make at least $4 per outfit on her kids' Gymboree clothes that she sells on eBay.
Their voices are high-pitched and sound like Gilbert Godfrey sucking helium.
Heliox is a mixture of 20 to 30 percent oxygen and 70 to 80 percent helium.
For example for the letter "B" you can read about Goldilocks and the three bears, make bubbles and buy a few helium balloons and write the capital letters and lower case letters on them.
Other targets include content sites such as Helium or Associated Content.
For those more adventurous souls, take a tethered helium balloon ride over Niagara and experience the area from a wildly different viewpoint.
Offered by the Flight of Angels, a helium air balloon takes its passengers four hundred feet up in the air.
It even featured a helium release valve for releasing helium gas build-up.
It also has a helium release valve, to keep pressure from building up when worn in high pressure enviroments.
Other features include helium escape valve for saturation diving, a soft iron secondary inner case to protect the movement from magnetism, and two shock resistant safety systems.
Rent a helium tank or order dozens of helium-filled balloons.
Some large apartment complexes and hotels have a helium tank, and the manager may allow you to fill some balloons if you offer to pay a reasonable amount for the helium that you use.
There is no need to purchase an expensive "bouquet" of helium balloons.
Avoid using lots of garish decorations like huge helium balloons or gaudy banners, and stick with more subtle décor.
Tie bundles of helium balloons to fence posts, or hang flags there.
Fill princess balloons with helium, and tie to the backs of chairs or bundle into balloon bouquets.
Norman Lockyer, and ascribed by him to a hypothetical element helium.
As director of the Cryogeen Laboratory, founded by him at Leiden, he succeeded, in 1908, in liquefying helium.
Frankland and Lockyer were also the discoverers of helium.
In 1868 they noticed in the solar spectrum a bright yellow line which did not correspond to any substance then known, and which they therefore attributed to the then hypothetical element, helium.
As the first condensation takes place, the resulting development of heat causes the hydrogen, helium and light gases to be expelled.
As the nuclei grow by the attraction of matter they begin to be capable of retaining the lighter gases, and atmospheres of hydrogen and helium are formed.
The temperature of the photosphere at this stage has reached a maximum, and the star is new of the helium type.
Then follows a gradual absorption of first the helium and then the hydrogen, the photosphere grows continually cooler, and the star passes successively through the stages exemplified by Sirius, Procyon, the Sun, Arcturus and Antares.
Some of the former are to be seen at the limb on most occasions; they may hang for days about the same place; they reach altitudes of which the average is perhaps 20,000 m., and show the spectral lines of hydrogen and helium.
The Indian eclipse of the 18th of August 1868 supplied knowledge of their spectrum, found to include the yellow ray of an exotic gas named by Sir Norman Lockyer " helium."
And in 1895, he set apart, as in the earliest stage of growth, a new class of " helium stars," supposed to develop successively into Sirian, solar, Antarian, or alternatively into carbon stars.
The typical helium atom consists of a nucleus of two protons and two neutrons surrounded by two electrons.
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Also you will not be able to use the helium to inflate foil balloons and all of the 30 latex balloons.
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Time of flight experiments can also be carried out by using a pulsed helium beam created using a beam chopper.
Often the magnet is a superconducting solenoid coil which requires cooling to the temperature of liquid helium.
To cool the sample, liquid cryogen is drawn from the helium reservoir, through a capillary tube and into a heat exchanger.
The researchers can cool a beam of hydrogen atoms using a helium cryostat to just 10 degrees above absolute zero.
The Phenix is a unique closed cycle helium cryostat specifically designed for powder diffraction.
Dewar (flask)nning the cryostat, liquid helium is transferred from a storage dewar into the bath reservoir.
Basically, the Hydrogen nuclei fuse together in a series of reactions to form Helium nuclei and energy.
Absorption by the forest gas in the equivalent resonance line of singly ionized helium also appears to be ubiquitous.
And then inhale the helium out the big can you will have to hire all in part of helping out Crowfield.
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It is Herschel's supply of superfluid helium which dictates how long its operational lifespan will be.
The solvent used in the experiment was liquid helium.
Helium is relatively abundant in many minerals, all of which are radioactive, and contain uranium or thorium as important constituents.
They have made this observation the basis of a practical method of separating helium from the other inert gases.
The density of helium has been determined by Ramsay and Travers as 1.98.
The spectrum of helium has been very carefully studied by Runge and Paschen.
At atmospheric pressure the discharge is able to pass through a far greater distance in helium than in the common gases.