David Ainley, Jake Baxter, and Benas Burdulis
__The Young Mendeleev__
Dmitri Ivanovich Mendeleev was born in Tobol's, 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.
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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.
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.
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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.
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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.
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.
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.
http://library.tedankara.k12.tr/chemistry/vol1/atomstr/trans50.jpg
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