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.
• 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,
• 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:
Boiling point increases
in nature, does
increase the life
of the filament
argon with 15
Liquid xenon is
used in bubble
chamber for the
the interior of
defects in steel
(less dense =
Neon lights are
fog and mist
tubes and radio
for producing high
speed flash of
bluish light used in
of cancer and
for the safety of