What Are Noble Gases?
- Noble gases are the elements in Group 18 of the periodic table.
- They include: Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), Radon (Rn), and Oganesson (Og).
- They are all colorless, odorless gases at room temperature.
Why Are They Chemically Inert?
- Noble gases have a full outer shell of electrons (complete valence shell).
- This makes them stable and they don’t need to gain, lose, or share electrons.
- Because of this, they hardly react with other elements → they are called inert gases.
Properties of Noble Gases
- Very unreactive (chemically inert).
- Low boiling and melting points.
- Do not easily form compounds (though Xe and Kr can form some under special conditions).
- Colorless and non-flammable.
Uses
- Helium: Balloons, breathing mixtures for divers.
- Neon: Neon lights.
- Argon: Shielding gas in welding, inside light bulbs.
- Xenon: Special lamps, anesthesia.
- Radon: Used in some cancer treatments.
In short:
Noble gases are Group 18 elements with full outer electron shells, making them very stable and unreactive.