Cobalt is number 27 on the periodic table. Its atomic mass is 58.9332 and its chemical symbol is Co.

 

 

When Cobalt is impure the ore’s color is azure. And it puts disease at ease to seize the cancer cells. Also it keeps the sheep’s wool well.

 

 

History

It is thought that humans have been using cobalt compounds since about 1400 BC, however it wasn’t officially discovered until 1735. It was then that Swedish scientist Georg Brandt discovered a dark blue pigment found in copper ore. Some were skeptical of Brandt’s discovery because of its similarity to copper, however Brandt showed that cobalt’s compounds were a much deeper blue than copper. Cobalt got its name from the German word Kobold. It means “goblin” or “evil spirit. Cobalt was described this way because miners said that it was very difficult to mine and damaged health. Historically Cobalt is very important to art. Craftsmen have used it for countless centuries. To learn more about the artistry of cobalt, see the art section.
   

Uses

Cobalt is used quite a lot in our world today. It is a big part of artistry, used to color glass, pottery and fabrics with its vibrant blue tone. The most used radioactive isotope of cobalt is cobalt 60. It is used to treat disease. For years it has been used to treat cancer. To do so the cobalt 60 kills the cancer cells through radiation. Along with cobalt 57 and 58 it is also used to see if the body is using vitamin B-12 properly, this is called a Schilling Test. B-12 is an essential element for health. In addition it is used for high temperature, heavy-duty cutting tool, magnetic steels, and stainless steels. Industrially, it is used in X-Rays, where the X-Ray machine can penetrate the human body. Also it is used in electroplating, which is when metals are coated with other metals, because of its appearance, hardness and resistance to oxidation. When cobalt is used carefully in the form of chloride, sulfate, acetate or nitrate is can correct mineral deficiencies in animals. It is also used in a supplement in a sheep’s diet to improve wool quality and prevent disease. Cobalt is used in food irradiation as well. When Cobalt 60 is exposed to food it preserves it. It kills bacteria and other organisms causing disease and spoilage. Food can be stored longer. Some think that this is harmful however there is no proof of negative effects.

Art

Cobalt is most valued for its vivid and rich blue color. It is put no different forms to be used in artwork where it has been an important part of the history of artistry. It is made into a powder to be mixed with liquids for paint. It is also used as a dye for fabrics. Substances and compounds of cobalt are used in glass, pottery, ceramics and more. The most common for of cobalt used in the arts, is called cobalt-blue. It is a compound of alumina and oxide of cobalt and is a beautiful pigment of blue. Also because of its profound color, the adjective of “cobalt blue” is used to describe paints and color in general. The distinct color of cobalt is how it is commonly known.

Properties

Cobalt is a hard, brittle, gray metal solid when it is pure. However when impure it can be a bright blue and change texture. It is very ductile making it good for artistry, yet only moderately malleable. Its boiling point is 1,493 degrees Celsius and has a melting point of 3,100 degrees Celsius. It has an average amount of reactivity and only catches fire if it is in the powder form. It is placed next to copper and nickel on the periodic table of the elements. It is often confused with these elements because they share most properties. The major thing that separates them is the blue pigment that cobalt has in it.

(Pictures from left to right, copper, cobalt and nickle)

Occurrence

Cobalt is relatively abundant on our earth. It has an estimated 10 to 30 parts per each million of element occurrence. Cobalt is in the top 1/3 of most plentiful elements. Cobalt’s most common ores are cobalite, smaltite and, linacite. Despite it’s rich occurrence, Cobalt is not mined in the United States. The major suppliers of cobalt are Canada, Zambia, Russia, Australia, Zaire, and Cuba.

(picture is a flag of Zambia, one of the biggest suppliers of cobalt)

Isotopes

Cobalt has 26 isotopes, 10 of which are radioactive. The radioactive isotopes are all synthesized except for cobalt 48, 49 and 51. The most used isotope of cobalt is cobalt 60. As shown in the uses section, cobalt 60 treats cancer through radiation as well as for the Schilling Test of testing the body for vitamin B-12.

(Picture on right is of a medical proocess for the treatment of trigemal neuralgia, involving cobalt-60 the radioactive isotope)

 

 

 

 

 

 

 

Table
Atomic Number 27
Atomic Mass 58.9332
Density 8.9g/cm3
Boiling Point

2927°
Melting Point

1495°
Classification Metallic
Group 9, transition metal
Period 4
Protons/electrons 27
Neutrons 32

 

Cobalt is often confused with copper and nickle. They share most of the same properties and are next to each other on the periodic table of the elements. To find out about the differences and what separates them visit these sites about copper and nickle.

 

Glossary
 

1. Electroplating: the process of coating metal with another metal
2. Irradiation: food preservation
3. Ore: a mineral containing metal valuable to be mined
4. Pigment: a dry color material especially to be mixed with a liquid
5. Oxidation: combination of a substance with oxygen
6. Deficiencies: to lack, the state of need something not present

 

Bibliography
 

1. "| Cobalt | Essential information." WebElements Periodic Table of the Elements. 10 Feb. 2009 <http://www.webelements.com/cobalt/>.

2. California Physical Science. p-139, 142. Boston: Pearson Prentice Hall, 2008.

3. "Cobalt." Los Alamos National Labs Chemistry Division. 25 Feb. 2009 <http://periodic.lanl.gov/elements/27.html>.

4. "Cobalt." SIRS Discoverer Login. 16 Jan. 2009 <http://discoverer.prod.sirs.com/discoweb/disco/do/article?urn=urn%3Asirs%3AUS%3BARTICLE%3BART%3B0000221541>.

5. "It's Elemental - The Element Cobalt." Science Education at Jefferson Lab. 16 Jan. 2009 <http://education.jlab.org/itselemental/ele027.html>.

6. Newton, David E. Chemical Elements. Vol. 1. Farmington Hills: Gale Group, 2006.


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