Helium

It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas, the first in the noble gas group in the periodic table.

The six noble gases that occur naturally are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and the radioactive radon (Rn).

Helium (from ἥλιος) is a chemical element with symbol He and atomic number 2.

The two lightest elements, hydrogen and helium, were mostly formed in the Big Bang and are the most common elements in the universe.

Its abundance is similar to this figure in the Sun and in Jupiter.

Roughly three quarters of the Sun's mass consists of hydrogen (~73%); the rest is mostly helium (~25%), with much smaller quantities of heavier elements, including oxygen, carbon, neon, and iron.

Its abundance is similar to this figure in the Sun and in Jupiter.

Jupiter is primarily composed of hydrogen with a quarter of its mass being helium, though helium comprises only about a tenth of the number of molecules.

For at least a portion of its life, a star shines due to thermonuclear fusion of hydrogen into helium in its core, releasing energy that traverses the star's interior and then radiates into outer space.

After hydrogen, helium is the second lightest and second most abundant element in the observable universe, being present at about 24% of the total elemental mass, which is more than 12 times the mass of all the heavier elements combined.

Giant clouds of hydrogen and helium were gradually drawn to the places where dark matter was most dense, forming the first galaxies, stars, and everything else seen today.

Most helium in the universe is helium-4, the vast majority of which was formed during the Big Bang.

Giant clouds of these primordial elements (mostly hydrogen, with some helium and lithium) later coalesced through gravity, eventually forming early stars and galaxies, the descendants of which are visible today.

After hydrogen, helium is the second lightest and second most abundant element in the observable universe, being present at about 24% of the total elemental mass, which is more than 12 times the mass of all the heavier elements combined.

As another example, looking at the mass-fraction abundance of hydrogen and helium in both the Universe as a whole and in the atmospheres of gas-giant planets such as Jupiter, it is 74% for hydrogen and 23–25% for helium; while the (atomic) mole-fraction for hydrogen is 92%, and for helium is 8%, in these environments.

This is due to the very high nuclear binding energy (per nucleon) of helium-4 with respect to the next three elements after helium.

Helium-4 (' or ') is a non-radioactive isotope of the element helium.

It was first detected as an unknown yellow spectral line signature in sunlight during a solar eclipse in 1868 by Georges Rayet, Captain C. T. Haig, Norman R. Pogson, and Lieutenant John Herschel, and was subsequently confirmed by French astronomer Jules Janssen. The line was detected by French astronomer Jules Janssen during a total solar eclipse in Guntur, India.

Pierre Jules César Janssen (22 February 1824 – 23 December 1907), also known as Jules Janssen, was a French astronomer who, along with English scientist Joseph Norman Lockyer, is credited with discovering the gaseous nature of the solar chromosphere, and with some justification the element helium.

Janssen is often jointly credited with detecting the element along with Norman Lockyer.

Along with the French scientist Pierre Janssen he is credited with discovering the gas helium.

A well-known but minor use is as a lifting gas in balloons and airships.

A balloon is a flexible bag that can be inflated with a gas, such as helium, hydrogen, nitrous oxide, oxygen, air or water.

A well-known but minor use is as a lifting gas in balloons and airships.

Helium gas has almost the same lifting capacity and is not flammable, unlike hydrogen, but is rare and relatively expensive.

It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas, the first in the noble gas group in the periodic table.

When grouped together with the monatomic noble gases – helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn) – these gases are called "elemental gases".

This radiogenic helium is trapped with natural gas in concentrations as great as 7% by volume, from which it is extracted commercially by a low-temperature separation process called fractional distillation.

Natural gas is a naturally occurring hydrocarbon gas mixture consisting primarily of methane, but commonly including varying amounts of other higher alkanes, and sometimes a small percentage of carbon dioxide, nitrogen, hydrogen sulfide, or helium.

It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas, the first in the noble gas group in the periodic table.

The inert gases are obtained by fractional distillation of air, with the exception of helium which is separated from a few natural gas sources rich in this element, through cryogenic distillation or membrane separation.

Liquid helium is used in cryogenics (its largest single use, absorbing about a quarter of production), particularly in the cooling of superconducting magnets, with the main commercial application being in MRI scanners.

In the field of cryogenics, helium [He] is utilized for a variety of reasons.

Ramsay was looking for argon but, after separating nitrogen and oxygen from the gas liberated by sulfuric acid, he noticed a bright yellow line that matched the D 3 line observed in the spectrum of the Sun.

By mass, oxygen is the third-most abundant element in the universe, after hydrogen and helium.

Lockyer and English chemist Edward Frankland named the element with the Greek word for the Sun, ἥλιος (helios).

He also studied luminous flames and the effects of atmospheric pressure on dense ignited gas, and was one of the discoverers of helium.

This is due to the very high nuclear binding energy (per nucleon) of helium-4 with respect to the next three elements after helium.

For that reason, the protons forming the nuclei of ordinary hydrogen—for instance, in a balloon filled with hydrogen—do not combine to form helium (a process that also would require some protons to combine with electrons and become neutrons).

It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas, the first in the noble gas group in the periodic table.

These are helium, neon, argon, krypton, xenon and radon.

On March 26, 1895, Scottish chemist Sir William Ramsay isolated helium on Earth by treating the mineral cleveite (a variety of uraninite with at least 10% rare earth elements) with mineral acids.

His work in isolating argon, helium, neon, krypton and xenon led to the development of a new section of the periodic table.

The line was detected by French astronomer Jules Janssen during a total solar eclipse in Guntur, India.

French astronomer, Pierre Janssen observed the Solar eclipse of 18 August 1868 and discovered helium, from Guntur in Madras State, British India.

This series is named for Edward Charles Pickering, who in 1896 published observations of previously unknown lines in the spectrum of the star ζ Puppis (these are now known to occur with Wolf–Rayet and other hot stars).

Wolf–Rayet stars, often abbreviated as WR stars, are a rare heterogeneous set of stars with unusual spectra showing prominent broad emission lines of highly ionised helium and nitrogen or carbon.

In 1907, Ernest Rutherford and Thomas Royds demonstrated that alpha particles are helium nuclei by allowing the particles to penetrate the thin glass wall of an evacuated tube, then creating a discharge in the tube to study the spectrum of the new gas inside.

Rutherford moved in 1907 to the Victoria University of Manchester (today University of Manchester) in the UK, where he and Thomas Royds proved that alpha radiation is helium nuclei.