4.8 NOBLE GASES

Noble gases, also known as inert gases, are a group of chemical elements found in Group 18 (or Group VIII-A) of the periodic table. They have general electron configuration ns², np⁶ except He, which has 1s². They are characterized by unique properties. They are odorless, colorless mono atomic gases and possess very low reactivity with other elements. This low reactivity is due to the presence of a complete valence shell, which makes them stable and unlikely to form chemical bonds with other elements under normal conditions. Noble gases include elements: Helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn), and oganesson (Og).

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Due to their non-reactive nature, noble gases are used in many ways, such as in lighting (e.g. neon signs), refrigeration systems and welding. They are also used in special applications, including filling gas exhaust lines and as a shielding gas in certain industrial processes.

Table 4.1: Electronic Configuration of Noble Gases

ElementAtomic NumberElectronic Configuration
Helium21s²
Neon101s²2s²2p⁶
Argon181s²2s²2p⁶3s²3p⁶
Krypton361s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶
Xenon541s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶4d¹⁰5s²5p⁶