1. The Noble Gases

2. General Properties
AKA"inert gases" due to the fact that their filled valence shells (octets) make them extremely nonreactive.
Characterized relatively late compared to other element groups.
Atomic mass, boiling point, and atomic radii INCREASE down a group in the periodic table.
Have the largest ionization energies, reflecting their chemical inertness.
All are monotomic gases under standard conditions behave similarly.

3. Helium 2nd most abundant element in the universe, but not on earth
Liquefied helium has cryogenic properties, and is used to freeze biological materials for long term storage and later use.
Twenty percent of industrial helium use is in wielding
Protects the heated parts of metals such as aluminum and titanium from air.
Used in tanks for underwater breathing devices

4. Neon Used in neon lighting and signs.
These neon lights are made with filled glass or plastic tubes with Neon gas.  
As electricity passes through these tubes, electric discharge produces high-energy electrons that hit the neon atoms changing their energy state, as photon of light is emitted.
These glass tubings can be shaped and twisted to form various designs.

5. Argon
Argon has been used in ordinary incandescent light bulbs to replace the oxygen that would otherwise shorten the lifetime of the filament.
It is used in some types of welding where active atmospheric gases would interfere with the process.
Argon is also used in various types of "black lights" or UV lamps since excitation of the gas produces a significant amount of ultraviolet radiation.
It is also used to fill dual pane glass windows and can prevent corrosion.

6. Krypton
Used in various kinds of lights, from small bright flashlight bulbs to special strobe lights for airport runways.
Due to it's large number of spectral lines, it's ionized gas is white, which is why light bulbs that are krypton based are used in photography and studio lighting in the film industry.
The most significant uses of Krypton is in the krypton- fluoride laser which is used in nuclear fusion energy research.

7. Xenon
This element is most notable for its bright luminescence in light bulbs.
Xenon is unique for being the first noble gas element to be synthesized into a compound.
Also used as a general anesthetic and plasma display panels.
HID Xenon headlights in cars are brighter, stable and more economically friendly than regular halogen light bulbs.
Good Ol video

8. Radon The primary source of indoor air pollution.
It sinks in air because it has a high density and is therefore often found in the basements of homes, particularly in areas where with a lot of shale and boulders in the soil.
Radon gas, along with decay products that can attach to dust and airborne particles, enters the lungs and decays, producing alpha and beta radiation that damages DNA and causes lung cancer.

9. He He Helium
Helium