Helium has a boiling point of 4.2K under 1 atm pressure, the lowest boiling point of any substance.
When an electric current is passed through a tube which contains Neon gas at a low pressure gas,
it has a red-orange glow.
Argon is colourless, odourless and tasteless. It makes up 0.934% of air.
Krypton is a dense, colorless, odorless atmospheric gas.
Xenon is a heavy, unreactive stable gas. When Xenon atoms are sufficiently energized, they produce a brilliant white light.
Chemical
Properties:
noble gases exist as single, monatomic gases atoms
all noble gases have eight
valence electrons, a completely filled outer energy level of electrons
('filled' outer shell means two electrons in the outer shell for He
and eight electrons in the outer shell for the others). This stable
electron arrangement accounts for the nonreactive nature of the noble
gases.
Abundance:
helium is extracted from natural gas wells
argon are present in about 1% of the Earth's atmosphere, other noble
gases are present in trace amounts
radon is a radioactive
gas produced from the radioactive decay of the element radium
Common
Compounds
and Usages:
helium is used to fill balloons, blimps, pressurize liquid fuel in
rockets
helium and argon are used in arc welding and metallurgical processes
to protect materials from reacting with nitrogen and oxygen in the air
argon and nitrogen are used to fill light bulbs and fluorescent tubes
to prolong the filament life
krypton is used to increase the efficiency and brightness of flashlight
bulbs and electronic flash in photography
neon is used to produce the bright orange-red light when electric
current is passed through a tube of neon gas at low pressure
Follow this interesting link to see more
pictures of the elements:
Section 5.2 
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