Learn The Uses of Inert Gases: Properties & Applications
Inert gases, also known as noble gases, are Group 18 elements that are chemically stable due to their complete outermost electron shells. These gases include Helium, Neon, Argon, Krypton, Xenon, and Radon, each with unique properties and applications. Their non-reactive nature makes them essential in industries, medicine, and scientific research. For example, helium is used in cryogenics and MRI machines, neon in lighting and signage, and argon in welding and insulation. Krypton and xenon play key roles in imaging and lighting technologies, while radon has applications in medical therapies and geological studies. This page explores the uses of inert gases across various fields, highlighting their importance in our daily lives and technological advancements.
What is Inert Gas?
Noble gases, also known as inert gases or Group 18 elements, are chemically stable due to their filled outermost orbitals. This stability makes them highly unreactive under normal conditions. They are colourless, odourless, tasteless, and non-flammable gases.
Key Facts:
Elements of group 18 are all gases and have filled outermost orbital, that's why these elements are highly stable and don’t react with other elements easily. This is the reason these elements are known as inert gases or inert elements.
The word inert means chemically unreactive. These gases are also known as Noble Gases. Group 18 is also called the zero group. So, elements of group 18 are also called zero group elements.
They are generally colourless, odourless tasteless, and non-inflammable gas. For many decades they are put into zero groups of the traditional periodic table as they are thought to be completely non-bonding to other atoms so that the atoms of the noble gases do not react with the atoms of any other elements for a new chemical compound.
Their structural identification along with the finding of their characteristics shows that in the special condition, they do react to form some of the special compounds and have correctly put them in group 18 of the modern periodic table.
As the atomic number of the noble gases increases their abundance in the atmosphere decreases. Therefore, after hydrogen, helium is the second most abundant gas that is found in the Earth’s atmosphere.
The most commercial methods of obtaining the Noble gases are in the air except for helium and radon and they are extracted out of the air by the liquefaction and fractional distillation methods.
Energy and particles, helium nuclei (alpha particles) and radon atoms are seen to be emitted out of the nuclei of the radium atom spontaneously.
Noble Gases List
Here we are providing a list of how many inert gases are there with their electronic configuration –
Properties of Noble Gases
Physical Properties
State: Gaseous at room temperature.
Colour/Odor/Taste: Colorless, odourless, and tasteless.
Non-Flammability: These gases do not support combustion.
Chemical Properties
Electronic Configuration:
General: $ns^2np^6$ (Helium: $1s^2$)
Their complete valence shell ensures chemical inertness.Atomic Radii:
Small atomic radii compared to other groups. The size increases down the group.Ionisation Energy:
Very high ionisation energies due to stable configurations. This decreases down the group.Electron Gain Enthalpy:
Positive values indicate a reluctance to gain electrons.Reactivity:
Noble gases form compounds only under special conditions, such as Xenon hexafluoride ($XeF_6$).
Discovery of Noble Gases
Applications of Noble Gases In Daily Life
Helium
Medical: Treatment of respiratory disorders like asthma.
Cryogenics: Coolant for superconductors and MRI machines.
Industrial: Welding and explosion prevention.
Recreational: Filling balloons.
Neon
Lighting: Signboards, lamps, and lasers.
Electronics: Used in television tubes and wave meter tubes.
Design: Creates vibrant colors for interior decor.
Argon
Welding: Provides an inert atmosphere for metal joining.
Lighting: Fills light bulbs to prevent filament corrosion.
Construction: Used in double-glazed windows for insulation.
Krypton
Lighting: Used in fluorescent lamps and high-speed photography flashes.
Medicine: MRI imaging of airways and nuclear scans.
Aerospace: Propellant for satellites.
Xenon
Medical: Imaging of the brain, heart, and lungs.
Industrial: Used in high-pressure arc lamps and lasers.
Scientific: NMR spectroscopy and bactericidal applications.
Radon
Medicine: Cancer and tumour therapy through radiation.
Earth Science: Predicts earthquakes by monitoring soil radon levels.
Research: Tracks air masses and geological faults.
Extraction of Noble Gases
Noble gases are primarily extracted from air, except for helium and radon:
Method: Liquefaction and fractional distillation of air.
Radon: Produced during the radioactive decay of radium.
Conclusion
Noble gases are vital for scientific, medical, industrial, and recreational purposes. Their unique properties make them irreplaceable in applications requiring chemical inertness. Advances in technology continue to unlock new uses for these remarkable elements.
FAQs on Uses of Inert Gases: Noble Gases in Everyday Life and Industry
1. What is an inert gas, and why are they also called noble gases?
An inert gas is an element from Group 18 of the periodic table. They are called noble gases because of their low chemical reactivity, similar to the historical reluctance of nobility to mix with commoners. This stability is due to their completely filled valence electron shells (a stable octet, or duet for Helium), which makes them highly unreactive under normal conditions.
2. Which elements are classified as noble gases?
There are seven elements classified as noble gases. The six that occur naturally are:
- Helium (He)
- Neon (Ne)
- Argon (Ar)
- Krypton (Kr)
- Xenon (Xe)
- Radon (Rn) (radioactive)
The seventh, Oganesson (Og), is a synthetically created element and is also part of this group.
3. Why are noble gases chemically unreactive?
Noble gases are chemically unreactive due to their stable electronic configuration. Their outermost electron shell is completely full, meaning they have very high ionisation enthalpies (energy required to remove an electron) and positive or near-zero electron gain enthalpies. This makes it energetically unfavourable for them to lose, gain, or share electrons to form chemical bonds under standard conditions.
4. What are some common uses of inert gases in daily life?
Inert gases have several applications we encounter daily:
- Lighting: Neon is used in vibrant advertising signs, Argon fills incandescent light bulbs to protect the filament, and Xenon is used in bright car headlights.
- Balloons: Helium's low density and non-flammability make it perfect for filling party and weather balloons.
- Insulation: Argon is often used between the panes of double-glazed windows to improve thermal insulation.
5. How are inert gases like Argon and Helium used in industrial processes?
In industry, the primary role of inert gases is to create a protective, non-reactive environment. For example:
- Welding and Metallurgy: Argon provides an inert atmosphere during arc welding, preventing the hot metal from oxidising and ensuring a strong, clean weld.
- Cryogenics: Liquid Helium, with its extremely low boiling point of -269°C, is used as a super-coolant for the powerful magnets in MRI machines and in scientific research requiring near-absolute zero temperatures.
6. What are the key medical applications of noble gases?
Noble gases have vital roles in medicine:
- Medical Imaging: Liquid Helium is essential for cooling the superconducting magnets in MRI scanners. Xenon can be used as a contrast agent for imaging the lungs.
- Respiratory Therapy: A mixture of Helium and Oxygen (Heliox) is less dense than air and can be administered to patients with severe breathing obstructions to ease airflow.
- Radiotherapy: The radioactive gas Radon has historically been used in small, sealed capsules for cancer therapy.
7. Since noble gases are inert, how is it possible to form compounds like Xenon hexafluoride?
The term 'inert' is relative. While they are unreactive under normal conditions, larger noble gases like Xenon and Krypton can form compounds. This is because their outermost electrons are further from the nucleus and less tightly held, resulting in lower ionisation energies compared to lighter noble gases. When reacted with highly electronegative elements like fluorine or oxygen under specific, high-energy conditions, they can be forced to share electrons and form chemical bonds.
8. Why is Helium used in weather balloons and airships instead of Hydrogen, which is lighter?
Although hydrogen provides slightly more lift, it is highly flammable and can form explosive mixtures with oxygen in the air. Helium, being a noble gas, is completely non-flammable and chemically inert. This inherent safety makes it the preferred choice for applications involving transport, public events, and scientific balloons, despite it being a more expensive and finite resource.
9. Is nitrogen considered an inert gas? How does its use compare to noble gases like Argon?
Nitrogen gas (N₂) is often used as an inerting agent for applications like food packaging, but it is not a noble gas; it is a Group 15 element. Its relative inertness comes from the very strong triple bond between its two atoms. However, in high-temperature processes like welding, nitrogen can react with hot metals to form nitrides, weakening the material. In these cases, a true noble gas like Argon is superior because it remains completely unreactive even at extreme temperatures.
10. Why are different noble gases like Neon, Argon, and Xenon used in different types of lighting?
The choice of noble gas for lighting depends on the colour and intensity of light desired, which is determined by the gas's unique atomic emission spectrum. When an electric current passes through the gas, its electrons get excited and emit photons of specific wavelengths upon returning to their ground state.
- Neon: Emits a signature, bright reddish-orange light.
- Argon: Emits a pale lavender light and is primarily used to prevent filament oxidation in traditional bulbs.
- Xenon: Emits an intense, bright white light that closely mimics natural daylight, making it ideal for car headlights and cinema projectors.
11. How do the physical properties of noble gases, like boiling point, influence their specific applications?
The physical properties, which change predictably down the group, are crucial for their applications. The boiling point increases down the group as the strength of the intermolecular van der Waals forces increases. This trend directly impacts their use:
- Helium's extremely low boiling point (-269 °C) makes it the only choice for achieving the ultra-low temperatures required in cryogenics for MRI machines and particle accelerators.
- Argon's relative abundance and ease of separation from liquid air via fractional distillation make it a cost-effective choice for large-scale industrial applications like welding.
