Is Helium a Noble Gas?

Helium is a noble gas classified as the first element in Group 18 of the periodic table. This classification stems from helium’s electron configuration of 1s², which represents a completely filled valence shell with no unpaired electrons, making it chemically unreactive in normal circumstances.

In this guide, we’ll explore helium’s fundamental properties as a noble gas. We’ll also examine its unique physical characteristics that set it apart from other elements and discuss its key industrial applications.

What Makes Helium a Noble Gas?

Helium earns its noble gas classification through its exceptionally stable electron configuration of 1s². This configuration means that two electrons occupy the first energy level with opposite spins. This arrangement ensures stability by fulfilling the octet rule in the first energy level, making helium the smallest noble gas atom with an atomic number of 2.

Helium’s extreme stability manifests in its lack of chemical reactivity under ambient conditions. This element shows no tendency to gain, lose, or share electrons, which historically positioned it as one of the most chemically inert elements known to science.

The energy required to remove helium’s first electron stands at 2,372.3 kJ/mol, among the highest of all elements.

Still, recent scientific breakthroughs have revealed that helium can form stable compounds under extreme pressure conditions exceeding 1.1 million atmospheres. In 2017, researchers successfully synthesized sodium helide (Na₂He), where helium atoms occupy spaces within a sodium lattice without forming conventional chemical bonds.

How Do Helium’s Properties Differ from Other Gases?

Helium has the most extreme physical properties of any known element, particularly at low temperatures. At standard conditions, it exists as a monatomic gas with a density of 0.1786 g/L, which makes it the second lightest elemental gas after hydrogen.

Helium’s boiling point of 4.222 K (-268.928°C) is the lowest boiling temperature of any substance on Earth. For perspective, this temperature is only about 4 degrees above absolute zero, where all molecular motion theoretically ceases.

Helium also has a melting point of 0.95 K (-272.2°C), which only occurs under elevated pressure of at least 25 atmospheres. Unlike other elements, helium does not solidify at standard atmospheric pressure, regardless of how cold it becomes.

Below 2.17 K, liquid helium-4 undergoes a remarkable transition to a superfluid. In this phase, it acquires zero viscosity and can:

• Flow without friction
• Climb container walls
• Pass through barriers that would stop normal liquids

This superfluid behavior demonstrates quantum mechanical effects on a macroscopic scale. The superfluid helium exhibits infinite thermal conductivity and unusual film flow characteristics that defy classical physics.

What Are the Key Industrial Uses of Helium Gas?

The main industrial uses of helium gas include:

• Semiconductor manufacturing – the semiconductor industry relies heavily on helium as an inert atmosphere gas during wafer processing and heat transfer applications where contamination must be avoided.
• Welding and metal fabrication – helium serves as a shielding gas for specialized processes requiring non-reactive environments. Its small atomic size and high thermal conductivity make it effective for protecting sensitive materials during high-temperature operations.
• Leak detection – manufacturing facilities use helium to test the integrity of sealed systems, from automotive components to aerospace equipment.
• Aerospace – the aerospace industry depends on helium for pressurizing liquid hydrogen and oxygen fuel tanks in rockets. Helium also purges systems requiring oxygen-free environments, ensuring safe operations in critical applications.
• Quality control – laboratories use helium in chromatography and analytical instruments where precise measurements require stable, inert conditions. Its consistency and purity make it ideal for calibrating sensitive detection equipment.

How Is Helium Used in Medical Settings?

Medical imaging is helium’s most critical healthcare application, where liquid helium cools superconducting magnets in MRI scanners to temperatures below 4 K. This extreme cooling enables the zero-resistance electrical currents required for high-field magnetic resonance imaging.

Modern MRI systems generally contain between 1,000-2,000 liters of liquid helium, with advanced designs reducing boil-off rates through improved insulation systems. The ongoing global helium shortage has driven innovation in MRI cooling technology, including helium recycling systems and alternative coolants.

Another common use is respiratory therapy, which relies on helium-oxygen mixtures (heliox) for patients with breathing difficulties. The low density of helium reduces the work of breathing and improves gas flow in obstructed airways.

Finally, cryogenic medical procedures rely on helium’s ultra-low temperatures for specialized treatments. Research facilities use helium cooling for experimental medical devices and quantum-based diagnostic equipment.

What Are the Supply Challenges with Helium?

While helium constitutes nearly 24% of the elemental mass in the universe, terrestrial helium represents only 5.2 parts per million in Earth’s atmosphere. This scarcity stems from helium’s low atomic mass, which enables atmospheric escape into space at rates exceeding production from natural radioactive decay.

Economically viable helium concentrations typically occur in specific natural gas fields where alpha decay of uranium and thorium has trapped helium over geological timescales.

Current global production falls short of demand, as Earth’s crust produces helium through natural radioactive decay at rates far below industrial consumption levels.

The non-renewable nature of terrestrial helium reserves drives conservation efforts across industries. Manufacturing facilities increasingly implement helium recycling systems to reduce consumption and manage costs.

Research into helium conservation methods focuses on improved recycling technologies and alternative cooling systems. These developments aim to address resource limitations while maintaining critical industrial and medical capabilities.

Leverage Helium’s Unique Properties

Helium’s classification as a noble gas reflects its fundamental chemical stability and unique physical properties that make it indispensable across industries. From semiconductor manufacturing to medical imaging, helium enables technologies that drive modern industrial processes and healthcare delivery.

As supply challenges continue to shape the helium market, industries must balance conservation efforts with operational requirements while exploring innovative solutions to ensure continued access to this critical noble gas.

Tyler O'Brien

Tyler is a results-driven marketing professional specializing in the industrial gases and equipment industry, bringing his 10 years of technical expertise and digital marketing acumen to the complex industrial gas B2B environment.