In this WebQuest, students do some Internet research
on neon signs. They learn about the different noble gases
that are used to produce colors in neon signs, and about
the chemistry involved in producing those colors. Students
find out a little about the discovery of neon and the history
of neon signs. Students answer some questions about neon
signs based on their Internet research. Finally, students
use what they have learned about neon signs and the noble
gases to design a piece of neon art.
While students are doing their Internet research, they
will try to answer the set of questions given. Each web
site has some of the answers to the questions. For some
questions, students will have to read through two or three
of the web sites. Students should be encouraged to explore
web sites beyond the prompts given, especially the sites
showing neon art, as they begin to design their own works
of neon art.
- Research the chemistry of the noble gases
neon, argon, krypton, xenon, and radon.
- Describe the chemical changes that occur when
electricity passes through noble gases to produce the
characteristic colors of neon signs.
- Identify three ways in which different colors
can be produced in neon signs.
- Design a piece of neon art and identify the gases
used to produce the colors used.
Students will use the Internet links given to find out
all about neon signs. They will learn about the chemistry
of the noble gases and how electricity passing through glass
tubing filled with these gases causes chemical changes that
produce light energy. Students will identify the noble gases
most commonly used in neon signs. They will also discover
how 150 different colors can be produced through use of
different types of glass tubing and combinations of gases.
Students will use the information they have gathered to
answer the set of questions and design a piece of neon art.
1 class period for research, answering the set of questions,
and designing a piece of neon art
As students progress through the list of web sites, you
may help them to focus on what they need to know to answer
the questions given. Students are not expected to become
experts in the chemistry of the noble gases. However, if
any students wish to spend more time on the chemistry of
these gases, you may encourage them to do so. Tell students
that although glass tubing can be bent into nearly any shape
prior to the insertion of the gases, most often it is sold
in lengths of 4, 6, and 8 feet. Their designs should take
these lengths into consideration. If students choose unusual
colors for their neon art they may have trouble identifying
what type of tubing is used for that color.
You may assign 10 points to each of the eight questions,
and 20 points to the design of a neon art piece, for a total
of 100 possible points. The answers to the questions are
given below. You may rate the answer to each question
by the following point scale: Excellent 9-10 points; Very
Good 7-8 points; Good 5-6 points; Satisfactory 3-4
points; Poor 1-2 points; and Unsatisfactory 0 points.
Questions about The Art of Neon
- Neon gas was discovered in 1898 by William Ramsey and
Morris Travers. The first neon lamp was produced by Georges
- Neon produces a reddish-orange color. Argon produces
a faint purple. Krypton produces a ghostly white. Xenon
produces a blue glow. No information exists on radon as
it is not used in neon signs.
- Neon and a combination of argon and mercury are the
most commonly used gases in neon signs.
- Neon tubes are capped off by two glass electrodes that
have wire passing from outside to inside. One of these
electrodes has a tubulation a small tube which remains
as a passage from outside to inside. Tubulations are sealed
to a pumping system. The pumping system has glass stopcocks
or valves that allow sections to be selectively opened
or closed. An ultrahigh vacuum pump pulls air out of the
tube while a high voltage transformer bombards and heats
the remaining air to produce temperatures in excess
of 500ºF. This allows the tube to achieve a higher degree
of purity. When a high vacuum is reached, and the tube
begins to cool, a small amount of inert gas is introduced
from a flask or a tank of pressurized gas. The tubulation
is then heated and as it is pulled it such inward to make
the tubes own seal.
- Electrical current bombards the inert gas atoms with
electrons, knocking some electrons out of their orbits,
thus ionizing the gas atoms. These free electrons collide
with other free electrons, sending them back towards the
gas atoms. When the free electrons collide with the atoms,
they are absorbed into the atoms, thus releasing energy
in the form of light.
- 1) Clear glass tubing with neon produces red or reddish-orange;
Clear glass tubing with argon produces faint purple. 2)
Some colors are produced by inert gases in tubing with
fluorescent powders painted or baked on the inside. 3)
Colored glass may be used in combination with neon or
argon and mercury to produce other colors.
- Neon signs can last for decades; most last at least
8 to 15 years.
- more than 150 colors
Once students have answered the questions, evaluated their
designs for neon art pieces. Make sure they have identified
the colors used, what gases produce those colors, and the
size of the finished piece of art.
Using information gathered from the Internet, students
should be able to answer the questions given about the chemistry
of the noble gases and about neon signs. Students should
be able to describe the chemical changes that occur as electricity
passes through these gases when they are confined within
the glass tubing of neon signs. Students should also be
able to identify the three ways in which glass tubing is
treated to produce a wide variety of colors when combined
with neon and argon and mercury. Students should be able
to discover that although krypton produces a ghostly white
color when electricity is applied, it is too faint to be
of use in neon signs.