What Are Noble Gases?

What Are Noble Gases is an important chemistry topic that helps students understand why certain elements don’t react with others. This concept is crucial for mastering trends in the periodic table and for connecting properties, uses, and applications of different groups of elements in science and everyday life.

What is What Are Noble Gases in Chemistry?

A noble gas refers to any element found in Group 18 of the periodic table. These elements include helium, neon, argon, krypton, xenon, radon, and oganesson. 

Noble gases are colourless, odourless, and tasteless gases known for being unreactive because of their complete outer electron shells. 

This concept appears in chapters related to electronic configuration, properties of elements, and chemical bonding, making it a foundational part of your chemistry syllabus.

Molecular Formula and Composition

Every noble gas exists as a single atom (monatomic) in its natural state. For example, helium is He, neon is Ne, and argon is Ar. These elements are categorized as nonmetals and all have a general outer shell configuration of ns²np⁶ (except for helium, which is 1s²). Their chemical formulas are written simply as their symbols.

Preparation and Synthesis Methods

Most noble gases are separated from the air by liquefying air and then using fractional distillation. Helium is mainly obtained from natural gas fields by cryogenic separation. Radon is produced by radioactive decay, and oganesson is made artificially in particle accelerators using fusion of lighter atoms.

Physical Properties of What Are Noble Gases

Noble gases are gases at room temperature and pressure. They are:

• Colourless, odourless, and tasteless
• Non-flammable and non-toxic in low concentrations
• Monatomic (exist as single atoms, not molecules)
• Have low boiling and melting points that increase down the group
• Insoluble or only slightly soluble in water

Chemical Properties and Reactions

Noble gases are famous for their lack of chemical reactivity. They have very high ionisation energies and almost zero tendency to form compounds because their valence shells are completely full. 

However, the heavier noble gases (like xenon and krypton) can sometimes form compounds with highly electronegative elements like fluorine and oxygen in special laboratory conditions.

Frequent Related Errors

• Confusing noble gases with oxygen or nitrogen (which are not Group 18 elements).
• Stating that noble gases never react—heavier ones like xenon and krypton can form rare compounds.
• Forgetting that helium only has two electrons in its shell, not eight.

Uses of What Are Noble Gases in Real Life

Noble gases have many everyday and scientific applications:

• Helium: Used in weather balloons, blimps, and MRI machines for cooling.
• Neon: Famous for bright neon lights and advertising signs.
• Argon: Used to create inert atmospheres for welding and in incandescent light bulbs.
• Krypton and Xenon: Used in high-intensity lamps, camera flashes, and some types of lasers.
• Radon: Sometimes used in medical treatments, though it is radioactive.

Explore more applications in Uses of Inert Gases on Vedantu.

Relation with Other Chemistry Concepts

The noble gases are closely related to the electronic configuration topic, especially the concept of filled shells (octet rule). They are different from halogens (Group 17), which are highly reactive. 

The stability of noble gases is an important reference point for understanding why other elements try to achieve similar electron arrangements through bonding.

Step-by-Step Reaction Example

Here is an example of how noble gas xenon reacts with fluorine to form xenon hexafluoride (XeF₆):

1. Place xenon gas in a reaction vessel with fluorine gas.

2. Heat the mixture or use electric discharge to initiate reaction.

3. Xenon and fluorine combine to form XeF₆:

4. XeF₆ is collected and purified.

Lab or Experimental Tips

Remember the noble gases by their position in the last group of the periodic table. All have full outer shells (except helium, which is full at 2 electrons). Vedantu teachers often use the phrase “He Never Arrived; Krypton eXplodes Rarely, Oddly” as a fun memory trick for Helium, Neon, Argon, Krypton, Xenon, Radon, and Oganesson.

Try This Yourself

• List all noble gases and their symbols in order of atomic number.
• Which noble gas is used in neon lights?
• Why do noble gases not react under normal conditions?
• What is the electron configuration of argon?

Final Wrap-Up

We explored What Are Noble Gases—their periodic table position, properties, reasons for stability, and daily uses. Understanding noble gases helps explain why elements react or stay inert. Discover more clear notes, examples, and class links for noble gases at Vedantu to boost your chemistry understanding and exam results.