HELIUM

Helium is a chemical element and noble gas with atomic number 2. 
Helium is a colorless, odorless, tasteless, non-reactive gas that is extremely light and is the second most abundant element in the universe after hydrogen.
Helium is relatively rare and is mainly obtained from natural gas deposits.

CAS Number: 7440-59-7
Molecular Formula: He
Molecular Weight: 4
EINECS Number: 231-168-5

Synonyms: Helium, Atomic helium, Helium-4, 7440-59-7, p-Helium, O-Helium, Helium (USP), Helium 4, Helium [USP], INS NO.939, E939, INS-939, 206GF3GB41, E-939, He, DTXSID7036402, CHEBI:30217, CHEBI:33681, 71086-78-7, CHEBI:30218, CHEBI:30219, RefChem:5878, HELIUM, USP, DTXCID5016402, CHEBI:30220, CHEBI:33315, 231-168-5, 275-187-7, helio, helium atom, [He], helium(0), EINECS 275-187-7, HSDB 553, EINECS 231-168-5, UN1046, UN1963, Helium element, UNII-206GF3GB41, Element Helium, Element:Helium, Element-He, Element:He, Helium (atomic), Helium (element), He (element), Helium, compressed, Hydridohelium(1+) ion, HELIUM [VANDF], HELIUM [HSDB], HELIUM [FCC], HELIUM [WHO-DD], HELIUM [MI], HELIUM [MART.], HELIUM [GREEN BOOK], Helium, compressed [UN1046] [Nonflammable gas], SCHEMBL16770, HELIUM [EP MONOGRAPH], HELIUM [USP MONOGRAPH], Helium, >=99.995%, Helium, >=99.999%, CHEMBL1796997, SWQJXJOGLNCZEY-UHFFFAOYSA-N, DTXSID801018818, DB09155, Helium, Messer(R) CANGas, 99.999%, Q560, E 939, NS00076386, D04420, Helium, refrigerated liquid (cryogenic liquid), Helium, compressed [UN1046] [Nonflammable gas], Helium, refrigerated liquid (cryogenic liquid) [UN1963] [Nonflammable gas], HELIUM;HYDROGEN AND HELIUM;HYDROGEN-HELIUM;LEAK DETECTION STANDARD LD-3;atomichelium;helium,compressed;Primarily commercial liquefaction plants;HELIUMIONS

Helium improves its value as a specialized industrial gas.
Helium belongs to the noble gas group (Group 18) and has a completely filled outer electron shell, which makes it chemically inert under normal conditions.
It does not easily form compounds with other elements.

Helium improves chemical stability and non-reactivity.
Physically, helium has the lowest boiling point of all elements (−268.9°C) and remains liquid only at extremely low temperatures.
It is much lighter than air and can easily escape Earth’s atmosphere into space.

This improves its usefulness in lifting and cryogenic applications.
Functionally, helium is mainly used as a lifting gas, cryogenic coolant, shielding gas, and pressurizing agent, because of its low density, inertness, and ability to remain liquid at very low temperatures.
It plays a critical role in scientific and industrial technologies.

This improves safety, cooling performance, and precision applications.
Helium is best described as a very light, inert noble gas used in cryogenics, balloons, medical imaging systems, scientific research, and high-tech industrial processes.
Helium is a colorless, odorless, and tasteless monoatomic gas with an atomic weight of 4, a density of 1.78 g per 1 at 0°C and 1 atmosphere pressure, and an aqueous solubility of 0.97 mL per 100 mL at 50°C. 

The Bunsen solubility coefficient (the volume, in mL, of gas at standard conditions dissolved per mL of liquid).
of helium at 38°C is 0.0086 in water, and 0.015 in olive oil. 
After hydrogen, helium is the most abundant element in the universe; these elements are believed to represent 76 and 23 percent, respectively, of all matter in the universe. 

The earth’s atmosphere, however, contains only 5 ppm of helium. 
Mineral gases from wells contain higher concentrations and serve as the principal source for industrial production. 
Helium is chemically very inert; it has a weak tendency to combine with other elements such as fluorine. 

Helium is usually marketed as compressed gas, with the USP grade containing not less than 99 percent helium.
Helium is a chemical element; it has symbol He and atomic number 2. 
It is a colorless, odorless, non-toxic, inert, monatomic gas and the first in the noble gas group in the periodic table.

Heliums boiling point is the lowest among all the elements, and it does not have a melting point at standard pressures. 
It is the second-lightest and second-most abundant element in the observable universe, after hydrogen. 
Helium is present at about 24% of the total elemental mass, which is more than 12 times the mass of all the heavier elements combined. 

Heliums abundance is similar to this in both the Sun and Jupiter, because of the very high nuclear binding energy (per nucleon) of helium-4 with respect to the next three elements after helium. 
This helium-4 binding energy also accounts for why it is a product of both nuclear fusion and radioactive decay. 
The most common isotope of helium in the universe is helium-4, the vast majority of which was formed during the Big Bang. 

Large amounts of new helium are created by nuclear fusion of hydrogen in stars.
Helium is especially important in quantum physics research, because when cooled to extremely low temperatures, it shows unusual quantum behaviors such as superfluidity, where liquid helium flows without friction.

Helium phenomenon is observed in helium-4 near absolute zero and is a key system for studying quantum mechanics at macroscopic scale.
This improves understanding of quantum fluids and fundamental physics.

In superconducting technology, helium is essential because many superconducting materials only function at temperatures close to absolute zero, which can only be maintained using liquid helium cooling systems.
This enables technologies like MRI scanners and advanced particle detectors.
This improves superconductivity applications and medical imaging.

In industrial gas separation, helium is recovered from natural gas fields where it is trapped in small concentrations, often requiring complex cryogenic separation and purification processes.
These helium-rich gas fields are rare and geographically limited.
This improves resource extraction and supply chain importance.

In space physics and atmospheric science, helium plays a role in studying planetary atmospheres because it is light enough to escape gravitational fields over time.
This is one reason why hydrogen and helium are rare in Earth’s atmosphere but abundant in the universe.
This improves planetary science understanding.

In metrology and calibration, helium is used as a reference gas in high-precision instruments due to its known physical properties and inert behavior.
It helps calibrate mass spectrometers, flow meters, and leak detection systems.
This improves measurement accuracy and laboratory standards.

Melting point: -272.2 °C (lit.)
Boiling point: -268.934 °C (lit.)
Density: 0.1785 (0℃)
vapor density: 0.14 (vs air)
solubility: slightly soluble in H2O; insoluble in ethanol
form: gas
color: colorless
Odor: at 100.00%. odorless
Water Solubility: 8.61 mL/1000 g H2O (101.32 kPa, 0°C)
Thermal Conductivity: 0.1513 W/(m·K)
Merck: 13,4645
Henry's Law Constant: 3.9×10⁻6 mol/(m3Pa) at 25℃
Dielectric constant: 1.0 (−269℃)
Stability: Stable; extremely unreactive.
InChI: 1S/He
InChIKey: SWQJXJOGLNCZEY-UHFFFAOYSA-N
SMILES: [He]
LogP: 0.280

Helium is widely used in cryogenic technology, especially for cooling superconducting magnets in devices such as MRI scanners and particle accelerators.
Because it remains liquid at extremely low temperatures, it is essential for maintaining superconductivity.
Helium improves medical imaging and advanced physics research.

In medical applications, helium is used in MRI machines to cool superconducting magnets, enabling high-resolution imaging of the human body.
Helium is also used in helium–oxygen breathing mixtures (heliox) for patients with respiratory difficulties.
This improves diagnostic accuracy and respiratory treatment.

In aerospace and space exploration, helium is used to pressurize fuel tanks in rockets and spacecraft because it is inert and does not react with fuels or oxidizers.
Helium ensures stable fuel flow in propulsion systems.
Helium improves launch safety and propulsion reliability.

In balloons and airships, helium is used as a lifting gas because it is lighter than air and non-flammable, unlike hydrogen.
This makes it much safer for commercial and scientific balloon applications.
Helium improves lifting safety and stability.

In leak detection systems, helium is used because its small atomic size allows it to escape through very tiny leaks, making it ideal for testing vacuum systems, pipelines, and sealed components.
Helium mass spectrometry is a standard industrial method.
Helium improves detection accuracy and system reliability.

In semiconductor manufacturing, helium is used as a cooling and carrier gas during chip production processes, helping control temperature and remove heat efficiently.
It is also used in plasma etching systems.
Helium improves precision and manufacturing quality.

In welding applications, helium is used as a shielding gas, often mixed with argon, to improve heat transfer and penetration in specialized welding processes such as aluminum and stainless steel welding.
Helium improves weld quality and strength.

In scientific research, helium is used in low-temperature physics experiments to study quantum behavior, superfluidity, and superconductivity.
Liquid helium enables experiments near absolute zero.
Helium improves fundamental physics understanding.

In deep-sea diving, helium is used in breathing gas mixtures (helium-oxygen or trimix) to prevent nitrogen narcosis and reduce breathing resistance at high pressure.
Helium allows safer deep dives.
Helium improves diver safety and performance.

In industrial pressurization systems, helium is used to pressurize fuel and hydraulic systems in extreme environments because it remains inert and stable under pressure.
Helium improves system reliability in harsh conditions.

In optical fiber manufacturing, helium is used as a cooling and purging gas during fiber drawing processes to maintain purity and thermal control.
This helps produce high-quality, low-loss communication fibers.
Helium improves telecommunications performance and signal quality.

In additive manufacturing and metal processing, helium is sometimes used in combination with argon to improve heat transfer during welding or 3D printing of high-performance alloys.
Its high thermal conductivity helps manage heat more effectively than argon alone.
Helium improves material quality and thermal control.

In medical respiratory applications, helium–oxygen mixtures (heliox) reduce airway resistance because helium is much less dense than air, making breathing easier for patients with obstructed airways.
It is used in emergency medicine and intensive care situations.
Helium improves respiratory efficiency and patient safety.

In balloon science and atmospheric research, helium is used in high-altitude research balloons that carry scientific instruments into the upper atmosphere to study weather, radiation, and cosmic rays.
Its low density and non-flammability make it ideal for safe long-duration flights.
Helium improves atmospheric data collection and research capability.

In resource economics and geopolitics, helium is considered a strategic resource because global supply is limited and dependent on a few natural gas sources, making it subject to shortages and price fluctuations.
This has led to national helium reserves in some countries.
Helium improves understanding of resource management and supply security.

Helium is the 73rd most abundant element on Earth, but it is the second most abundant element in the universe, after hydrogen. 
Together, helium and hydrogen make up 99.9% of all the elements in the universe, but helium makes up only a small trace of the elements on Earth.
Most likely, helium was the first element to be formed after hydrogen during the Big Bang formation of the universe. 

The theory is that hydrogen atoms combined under great heat and pressure to form helium atoms. 
The Earth s current helium originally came from the natural decay of radioactive elements deep in the Earth. 
Much of it seeps up to the surface and escapes into the atmosphere, or it mixes with natural gas deposits deep in the Earth. 

Like hydrogen, it is a very light gas that escapes through cracks in the Earth s crust and sooner or later escapes from Earth s gravity into the atmosphere.
Helium is commonly stored in high pressure cylinders, hydril tubes, or tube trailers. 

Liquid helium is commonly stored at the consumer site in cryogenic liquid cylinders, portable customer stations, and specially designed insulated tanks. 
To minimize helium transfer losses, the shipping container for liquid helium is normally used for storage.

Uses Of Helium:
Helium is used to inflate weather balloons and lighter-than-air ships (blimps)similar to the ones seen taking TV pictures above football games. 
Even though helium has lesslifting power than hydrogen, it is used for all lighter-than-air ships because it is noncombustibleand thus safer than hydrogen. 
In addition to blimps, toy balloons are filled with helium.

In arc welding, it is used as an inert gas shield that releases great heat for very long andheavy welds. 
Helium prevents oxidation of the metal being welded, thus preventing burningand corrosion of the metal. 
This is one of the major uses of helium.

Helium is used for low-temperature research (–272.2°C or –434°F). 
Helium has become importantas a coolant for superconducting electrical systems that, when cooled, offer little resistance to theelectrons passing through a conductor (wire or magnet). 
When the electrons are “stripped” fromthe helium atom, a positive He++ ion results. 

The positive helium ions (nuclei) occur in bothnatural and man-made radioactive emissions and are referred to as alpha particles. 
Helium ions(alpha particles) are used in high-energy physics to study the nature of matter.

Helium is used as an inert gas shield in arc welding, as a lifting gas for lighter-than-air aircraft, and as a gaseous cooling medium in nuclear reactors. 
Helium is also used to provide a protective atmosphere for growing germanium and silicon crystals for transistors, to provide a protective atmosphere in the production of such reactive metals as titanium and zirconium, to fill cold-weather fluorescent lamps, to trace leaks in refrigeration and other closed systems, and to fill neutron and gas thermometers. 
Its thermal conductivity makes it an important gas for lasers and fiber optic production. 

Helium is used extensively in chromatography due to its inertness and high thermal conductivity. 
It is used in cryogenic research such as for superconductivity. 
In mixtures with oxygen, it has medical and diving applications. 

Radioactive mixtures of helium with krypton are available to users licensed by the Nuclear Regulatory Commission. 
NASA uses helium for purging and pressurizing the liquid hydrogen tanks of spacecraft because it is the only element that remains a gas in the extreme cold necessary to maintain the liquid hydrogen fuel used in many rockets and the Space Shuttle. 
Liquid helium is used for cooling superconductive magnets, used in magnetic resonance imaging, and in magnetic separation.

Helium is mainly used as a cryogenic coolant, lifting gas, shielding gas, pressurizing agent, and leak detection gas because it is very light, inert, and remains liquid at extremely low temperatures.
In MRI and cryogenics, it is used to cool superconducting magnets.
This improves medical imaging performance.

In balloons and airships, it is used as a lifting gas.
Helium improves safety and buoyancy.
In rocket and spacecraft systems, it is used to pressurize fuel tanks.

Helium improves propulsion reliability.
In leak detection, it is used to find very small leaks in systems.
Helium improves industrial safety and precision.

In welding and semiconductor manufacturing, it is used as a shielding or carrier gas.
Helium improves material quality and process control.
Helium is mainly used as a cryogenic coolant, lifting gas, shielding gas, leak detection gas, and pressurizing agent because it is inert, extremely light, and remains liquid at very low temperatures.

In MRI and superconducting systems, it is used to cool magnets.
Helium improves medical imaging and scientific research.
In balloons and airships, it is used as a lifting gas.

Helium improves safety and buoyancy.
In leak detection systems, it is used to find micro-leaks in equipment.
Helium improves industrial safety and precision.

In rocket systems, it is used to pressurize fuel tanks.
Helium improves spacecraft reliability.
In welding and semiconductor manufacturing, it is used as a shielding or process gas.

Helium improves product quality and process control.
Helium is mainly used as a cryogenic coolant, lifting gas, shielding gas, leak detection gas, and pressurizing gas because it is extremely light, chemically inert, and remains liquid at very low temperatures.

In medical MRI systems and superconducting magnets, it is used as a cryogenic coolant.
Helium improves imaging performance and system stability.
In balloons and airships, it is used as a lifting gas.

Helium improves safety and buoyancy.
In rocket and spacecraft systems, it is used to pressurize fuel tanks.
Helium improves propulsion reliability.

In leak detection equipment, it is used to detect very small leaks in pipelines and sealed systems.
Helium improves industrial safety and accuracy.
In welding and semiconductor manufacturing, it is used as a shielding or process gas.

Helium improves material quality and process control.
In deep-sea diving gas mixtures, it is used in heliox or trimix to reduce breathing resistance at high pressure.
Helium improves diver safety and performance.

Safety Profile Of Helium:
Helium is considered a very low-toxicity, non-reactive gas, but it still has important physical hazards related to oxygen displacement and pressure systems.
The main hazard is asphyxiation in confined spaces, because helium can displace oxygen without warning.
Since it is colorless, odorless, and non-irritating, oxygen levels can drop unnoticed.

Helium can lead to dizziness, unconsciousness, or death.
Inhalation of helium itself is not toxic, but breathing helium-rich gas prevents oxygen uptake, leading to hypoxia (oxygen starvation).
This is the same danger seen with other inert gases.

This improves confined-space safety awareness.
Breathing helium directly from pressurized sources (like balloons or tanks) can be dangerous because it may cause lung damage or gas embolism due to rapid pressure changes.
Helium can be life-threatening in extreme cases.

This improves pressure safety awareness.
Liquid helium presents a cryogenic hazard, causing severe cold burns and tissue damage on contact due to extremely low temperatures.
Special protective equipment is required for handling.

Helium improves cryogenic safety.
Pressurized helium cylinders pose a physical explosion risk if damaged, heated, or improperly handled.