wiki Word: Rare Earth Elements

Definition: Rare Earth Elements are the elements classified as lanthinides and actinides.

Info

It is not clear whether rare earth elements are just the lanthinides, because some people believe that they both lanthinides and actinides are classified as rare earth elements.

Rare Earth Elements are any of the abundant metallic elements of atomic number 57 through 71. and the chemical elements with atomic numbers 21 and 39.  These elements were originally thought to be rare and were therefore named the rare earth elements.  In fact, they are neither rare or are they earths.  These elements are classified as those of the lanthanide series and actinide series.  They usually occur together in minerals and were originally thought to be scarce.  Actually, they are abundant.  The metals never occur free.  The early uses of the rare earths were mostly  in the glass such as ceramic, lighting and metallurgic industries.  When heated, these elements give off an intense white light which resembles sunlight.

The principle economic source of these elements are the rare earth minerals.  These include: bastnasite, monazite, and loparite and the lateric ion absorption clays.  These are difficult to mine which makes them expensive. 

Some of the major properties of rare earth elements are

• Rare Earth Elements are a silvery-grayish color.
• The metals have a high luster but tarnish easily.
• The metals conduct electricity very well.
• These elements share many common properties. this makes them hard to tell one from another.
• The rare earth elements occur naturally together in minerals.

.

Pictures

These are examples of a rare earth element(left) and rare earth ore(right).

The term "rare earth elements" is used in the real world in fields such as geology and other  sciences requiring knowledge about elements and the periodic table. This word needs to be  understood in science because, it describes a rather large amount of elements in the periodic table. The reason we should study this term is very simple just the fact that we are learning about elements and the periodic table makes it a term we just need to know.

Bibliography

Info came from:

1) http://www.answers.com/topic/rare-earth-element?cat=technology&print=true

2) http://chemistry.about.com/od/elementgroups/a/rareearths.htm?p=1

Pictures came from:

 1) http://z.about.com/d/chemistry/1/G/d/Q/lanthanum.jpg

 2) http://en.wikipedia.org/wiki/Image:RareEarthOreUSGOV.jpg