Introduction Noble gases

Noble gases Introduction Occurrence and Uses

1. Noble gases Occurrence and Uses Dr. Mithil Fal Desai Shree Mallikarjun and Shri Chetan Manju Desai College Canacona Goa

2. s block d block p block Noble Gases f block Where are Noble Gases in periodic table? Group 18

3. Atomic number Noble Gases Symbol State (at Rt ) Electronic configuration 2 Helium He Gas 1s 2 10 Neon Ne Gas [He]2s 2 2p 6 18 Argon Ar Gas [Ne]3s 2 3 p 6 36 Krypton Kr Gas [ Ar ] 3d 10 4s 2 4 p 6 54 Xenon Xe Gas [Kr] 4d 10 5s 2 5 p 6 86 Radon Rn Gas [Xe] 4f 14 5d 10 6s 2 6 p 6 Noble Gas electronic configuration

4. Occurrence Element Abundance in atmosphere (% volume) He 5 x 10 -4 (~ 5 ppm) Ne 2 x 10 -4 Ar 0.93 Kr 1 x 10 -4 Xe 9 x 10 -6 Rn Radioactive Natural occurrence -Atmosphere -Natural gas reservoirs -Radioactive decay +  

5. Uses (He) -in cryogenic studies (B.P. 4 K) superconductivity/ lazer -cooling gas in nuclear reactor -flow gas in gas-liquid chromatography -weather balloons and airship Uses (Ne) -in neon discharge tubes (reddish-orange glow)

6. Uses ( Ar ) -in metallurgical process to provide inert atmosphere -welding (stainless steel, titanium, aluminium, magnesium) -growing germanium and silicon crystal, -electric bulbs -fluorescent lamp, -radio valves -Geiger-Muller radiation counter -purging in catalytic reactors -flow gas in gas chromatogram

7. Element He Ar N 2 H 2 Reactivity Inert Inert Less reactive reducing Economics Expensive Costly Relatively cheap Costly Availability Trace Relatively abundant noble gas Abundant Derived from naphtha cracking and electrolysis A comparative statement Non noble elements