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Mendeleev and the periodic table

Page history last edited by PBworks 14 years, 9 months ago

David A, Jake, and Benas

 

The Young Mendeleev

Dmitri Ivanovich Mendeleev was born in Tobol'sk, Siberia on February 7th of 1834. There are many variations of the spelling of his last name, including Mendeleyev and Mendelev. He was the youngest of 17 children of the head of a local high school. Mendeleev's Father went blind when he was only a child, leaving his mother to take care of the entire family. Because the area in which Mendeleev grew up and was educated was considered quite backward, he couldn't gain admission to any universities for quite some time.

http://web.visionlearning.com/events/images/Mendeleev_young.jpg

 

However, in 1855 he became a teacher at a local school and was finally allowed several years later to take an advanced degree in chemistry. He later finished his studies at the University of Heidelberg in Germany. After ending his studies several years later, Mendeleev returned to St. Petersburg, becoming a Professor of General Chemistry in 1864. There he published books on chemistry, several of which were translated into English and made Mendeleev internationally famous.

 

His Achievements

At the time, atomic weight was calculated by finding the product of valency and equivalent weight, often giving wrong results. Mendeleev found a way to fix this problem by correcting the valency of, fitting the elements together in a much more logical way. He also looked at the chemical properties of elements, rearranging the elements by these, rather than by atomic weight.

 

Mendeleev listed the elements in columns in order of increasing atomic mass. He then rearranged the columns so that the elements with the most similar chemical properties were side by side. This correctly arranged the elements, with many blank spaces remaining in between.

http://upload.wikimedia.org/wikipedia/commons/5/5f/Mendeleev_Table_5th_II.jpg

 

These blank spaces allowed Mendeleev to predict three new elements. In 1875, he predicted Gallium, in 1879, Scandium, and in 1886, Germanium. These are all named after countries or regions, Gaul being an old term for France. Scientists later on validated his predictions, showing that his work of arranging the elements was all correct.

 

There were only 66 elements in Mendeleev's final table, Uranium having the highest atomic number of 92.

 

http://upload.wikimedia.org/wikipedia/commons/2/26/Дмитрий_Иванович_Менделеев_4.gif

 

Mendeleev died at the age of 72 in St. Petersburg on February 2nd of 1907 and he has had an element, Mendelevium, named after him.

 

Advancements Since Mendeleev

Since Mendeleev's time, elements have been rearranged on the periodic table by atomic number, rather than by atomic weight, being that atomic number has more to do with an element's chemical properties. Atomic number is the number of protons in an atom's nucleus, also the number of electrons in a neutral atom.

 

The Periodic Law

"Periodic law is the generalization that there is a recurring pattern in the properties of the elements when they are arranged in order of increasing atomic number."("Periodic Law")

http://library.tedankara.k12.tr/chemistry/vol1/atomstr/trans50.jpg

 

Bibliography

"Development of the Periodic Table". __Chemistry: The Central Science__. Upper Saddle River, New Jersey: Prentice Hall, 1997. Pages 223-225, 248.

 

"Dmitri Mendeleev". __Wikipedia, The Free Encyclopedia__. Wikimedia Foundation, Inc., 2006 <http://en.wikipedia.org/wiki/Dmitri_Ivanovich_Mendeleev>

 

"Mendeleyev, Dmitri Ivanovich". __Hutchinson Dictionary of Scientific Biography__. Helicon Publishing Ltd., 1999. <http://www.accessscience.com/server-java/arknoid/science/AS/Biographies/5/447.html>

 

"Periodic Law". __Encyclopedia Brittanica Online__. Encyclopedia Brittanica, 2006. <http://www.brittanica.com/eb/article-9110603>

 

"Periodic Table". __McGraw-Hill Encyclopedia of Science and Technology__. McGraw-Hill, 2002. Pages 159-162.

 

"The Periodic Table of the Elements". __American Institute of Physics__. Long Island, New York: American Institute of Physics, 2006. <http://www.aip.org/history/curie/periodic.htm>

 

"The Periodic Table: Organizing The Elements". __Chemistry__. Upper Saddle River, New Jersey: Prentice Hall, 2002. Page 123.

 

Woods, Gordon. "The Development of the Periodic Table - Dmitri Mendeleev". __Chemsoc - Presenting Science__. Cambridge, UK: Royal Society of Chemistry, 2006. <http://www.chemsoc.org/networks/learnnet/periodictable/pre16/develop/mendeleev.htm>

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