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Transition metals are very important to industry. Iron is the main
part of steel. Steel is a material used for bridges and buildings. Most
electric wires and many other electrical devices are made of copper.
Copper is also used to make water pipes. It would be hard to think of an
industry that doesn’t make use of transition metals.
Some transition metals may be less familiar, but they are still
important for modern technology. The tiny coil of wire inside
incandescent light bulbs is made of tungsten. Platinum helps automobile engines burn fuel more cleanly.
Often, two or more metals are combined to form an alloy. Alloys
can be stronger, less likely to rust, or easier to shape than pure metals.
For example, steel is iron that contains other metals such as nickel,
chromium, or manganese. Brass, an alloy of copper and zinc, is stronger
than either metal alone. Silver jewelry often contains some copper,
making it stronger than pure silver.
Rare Earth Elements
Rare Earth Elements
Two rows of elements are set below the main periodic table. You have
read that this was done to save space. The top row is the rare earth
elements. These elements are often referred to as lanthanides because
they follow the element lanthanum (La) on the table. They are called
rare earth elements because scientists once thought that they were
available only in tiny amounts in Earth’s crust. As mining methods
improved, however, the rare earths were found to be not so rare—just
hard to isolate in pure form.
More and more uses are being found
for the rare earth elements. For example,
neodymium (Nd) is useful for making
cheap yet very powerful permanent
magnets. Cerium (Ce) is used in the
walls of self-cleaning ovens to prevent
the build up of grime. Most often,
however, the rare earths are used to add
color to glass. Europium (Eu), for
example, is used as a coating for some
television tubes. Praseodymium (Pr)
provides a protective coating against
harmful radiation in the welder’s
helmet in the photograph.
218 Unit 2: The Structure of Matter
MAZER
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