2.3  Noble Gases

Noble gases are colorless, orderless, tasteless and non flammable gases that can be found in the group 0 of the periodic table. You could imagine them as smug nobles that don't like to do anything or work but just sit around. They dont really react with anything under normal conditions but there are special cases where scientists can get noble gases to react to form compounds. However, the products are not very stable and break down easily.

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Unlike halogens, noble gases are monoatomic not diatomic. They have very stable structures since their electron shells are always filled. They have all the electrons they need, no more no less; therefore, they don't need to react with anything. However, they can become reactive if pressure is increased or temperature decreased significantly. Flurorine is able to react with some of the noble gases, particularly with krypton and xenon. 

As we discussed in the earlier chapter, fluorine is one of the most reactive elements in the periodic table. Therefore, it reacting with the larger atoms of noble gases is no surprise because the electrons in furthest shell of large atoms are not strongly attracted. Since xenon and krypton have larger structures, fluorine is able to react with them by pulling the weak electrons to form small amounts of a stable product.

The boiling points and melting increase down the group although not by a large amount. The density also increases down the group.

Uses of Nobles Gases

Nobles gases' inert property makes them very useful.

Argon is used in light bulbs to produce an inert atmosphere for the tungsten filament to glow. If instead of a noble gas, air was used, the filament will burn away in a flash because of oxygen. But since argon is unreactive even at very high temperatures, incandescent light bulbs can last for a fairly long time. 

Helium is used in airships since it is very light and inflammable. 

Xenon is widely used in medical applications. It is used as an anesthetic and medical imaging. It is also used in car headlamps because it produces a very bright white light. They are better than halogen lamps because they more efficient and not as harmful to the environment.

Similarly, neon is also used in lighting. It can be combined with other gases to produce lights with different colors

Krypton is used in lasers and headlamps as well.

Radon is used in radiotherapy due to its radioactivity.