Inert Gases

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Inert Gases

Inert Gases and Characteristics
• The inert gases are obtained by fractional
distillation of air.
• They are often used aboard chemical tankers and
product carriers (smaller vessels).
• Helium, Neon, Argon, Krypton, Xenon, Radon and
are inert gases.
• Duplet (Helium) or Octet
• Full valence shell






Weak interatomic force
Very low melting and boiling points.
Monatomic gases under standard conditions
Helium has several unique qualities when compared
with other elements:
– Boiling and melting points are lower than those of any
other known substance
– Only element known to exhibit super fluidity
– Only element that cannot be solidified by cooling under
standard conditions—a pressure of 25 standard
atmospheres (2,500 kPa; 370 psi) must be applied at a
temperature of 0.95 K (−272.200 °C; −457.960 °F) to
convert it to a solid.

History
• Noble gas is translated from the German noun
Edelgas, first used in 1898 by Hugo Erdmann to
indicate their extremely low level of reactivity.
• The name makes an analogy to the term "noble
metals", which also have low reactivity.
• Pierre Janssen and Joseph Norman Lockyer
discovered a new element on August 18, 1868 while
looking at the chromosphere of the Sun, and named
it helium after the Greek word for the Sun, ήλιος
(ílios or helios).

• Lord Rayleigh theorized that the nitrogen extracted
from air was mixed with another gas, leading to an
experiment that successfully isolated a new
element, argon, from the Greek word αργός (argós,
"inactive").
• With this discovery, they realized an entire class of
gases was missing from the periodic table.
• During his search for argon, Ramsay also managed
to isolate helium for the first time while heating
cleveite, a mineral.

• In 1902, having accepted the evidence for the
elements helium and argon, Dmitri Mendeleev
included these noble gases as group 0 in his
arrangement of the elements, which would later
become the periodic table.
• Ramsay continued to search for these gases using
the method of fractional distillation to separate
liquid air into several components.

• In 1898, he discovered the elements krypton, neon,
and xenon, and named them after the Greek words
κρυπτός (kryptós, "hidden"), νέος (néos, "new"), and ξένος (xénos, "stranger"), respectively.
• Radon was first identified in 1898 by Friedrich Ernst
Dorn, and was named radium emanation, but was
not considered a noble gas until 1904 when its
characteristics were found to be similar to those of
other noble gases.
• Rayleigh and Ramsay received the 1904 Nobel
Prizes in Physics and in Chemistry, respectively, for
their discovery of the noble gases

Colors and spectra (bottom row) of electric discharge in noble gases; only the top and second rows represent pure gases.

Down the group:
Density increases
Boiling point increases

Helium

Neon

Argon

Krypton

Xenon

Radon

High thermal
conductivity
and low
viscosity, inert
in nature, does
not undergo
corrosion,
unaffected by
irritation

Neon discharge
lamps and
advertising
signs
R.A.M. 20g/mol

Filling electric
bulbs to
increase the life
of the filament
(Mixture of
argon with 15
percent
nitrogen)

High
efficiency
miners' cap
lamps

Liquid xenon is
used in bubble
chamber for the
detection of
gamma photon
and neutral
mesons

Photographing
the interior of
opaque
materials for
locating the
defects in steel
castings

Floating
Balloons,
Squeaky Voice
(less dense =
high frequency)
R.A.M. 4g/mol

Neon lights are
visible from
long distances,
better
penetrating
power through
fog and mist

Filling
fluorescent
tubes and radio
valves

Filling
luminous
tubes, Laser

Discharge tubes
for producing high
speed flash of
bluish light used in
quick photography

Preparation of
ointment for
the treatment
of cancer and
other diseases

Beacon lights
for the safety of
air...
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