Is Helium Reactive?

No, helium is not reactive – it’s a noble gas with a full outer electron shell. Helium’s stable configuration prevents it from forming chemical bonds with other elements under normal conditions.

In this guide, you’ll learn more about what makes helium non-reactive. We’ll then cover its main applications, guidelines for safe handling, and environmental interactions.

Understanding Helium’s Chemical Nature

The extremely low reactivity of helium stems from its atomic structure. With only two electrons perfectly filling its outer shell, helium achieves what chemists call a “duet configuration.”

This electronic arrangement is exceptionally stable – the atom doesn’t gain, lose, or share electrons with other elements. So, helium is immune to these processes that typically drive chemical reactions.

How Reactive Is Helium?

Unlike many other elements, helium does not form compounds easily – and under normal conditions, it doesn’t form them at all.

Scientists have tried creating helium-based compounds in extreme laboratory settings, such as under very high pressures. Even then, the results are rare, unstable, and not practically useful.

One example is a compound called Na₂He (sodium helide), synthesized under ultra-high pressure. It exhibits unusual bonding characterized by an eight-center, two-electron bond structure, representing one of the few known compounds containing helium in any form of chemical bonding.

Why Helium Stays Inert Under Normal Conditions

Thanks to its atomic structure, helium has an exceptionally high ionization energy of 2372.3 kJ/mol. This means it takes tremendous energy to remove an electron from a helium atom.

In practical terms, helium won’t react with other elements (though it can form compounds at extreme pressures usually not found on Earth). Under typical conditions, helium remains chemically inert – even when exposed to:

• High temperatures
• Strong acids
• Strong bases
• Oxidizing agents

This chemical inertness makes helium particularly valuable in industrial processes where contamination must be avoided at all costs.

Further Reading: Is Helium Flammable?

Helium’s Non-Reactivity is Useful for Industrial Applications

Helium’s non-reactive nature supports various industrial processes, such as:

• Welding: in welding operations, helium serves as a shielding gas that prevents unwanted chemical reactions that could compromise weld quality.
• Medical uses: helium is mixed with oxygen in breathing support devices because it won’t react with other gases or the human body.
• Fiber optic cable production: in the manufacturing of fiber optic cables, helium’s inert properties create the environment necessary for producing ultra-pure glass fibers.

Considerations When Handling Helium

While helium is not reactive, it requires careful handling. 

Due to its extremely low boiling point of -268.9°C, helium must be stored in specially designed containers.

Helium can escape through tiny openings because of its small atomic size, which calls for proper storage solutions. Specifically, stainless steel and aluminum containers are commonly used for helium storage because they have very low permeability.

Fun fact: Helium atoms are so small they can squeeze through solid materials. This is why helium-filled balloons deflate overnight even when properly tied.

Even though helium won’t react chemically, it can pose physical challenges in industrial settings, such as:

• Accumulation in confined spaces due to high leakage rate
• Risk of asphyxiation as a result of oxygen displacement
• Cryogenic burns (in case of liquid helium)
• Sudden pressure buildup in sealed systems if helium warms up

To avoid these issues, proper temperature and pressure conditions are crucial when transporting and handling helium.

The key guidelines to follow include:

• Always transport cylinders in an upright position and secure them with straps or chains to prevent tipping or rolling.
• Ensure the protective cap is in place over the valve during transport to prevent damage or accidental release of gas.
• Transport helium in well-ventilated vehicles to prevent oxygen displacement in case of a leak.
• Ensure cylinders are clearly labeled with proper hazard symbols and that all required shipping documents are on hand.

Leverage Helium’s Non-Reactivity

Helium’s combination of chemical inertness and unique physical properties – such as low boiling point, low density, and high thermal conductivity – makes it indispensable across a wide range of industries. 

Further Reading: What Is Liquid Helium Used For?