(Dimitri) Mendelejew

15 October 2012 Last Updated on 26 August 2013 volunteer
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Dimitri Mendelejew (1834- 1907)

has succeeded to tabulate the periodic system (short: PSE= periodic system of elements) which contains every chemical element. He started the system to impose beginning with the smallest to the biggest element. When there were any properties in common, he put them into groups and in the periodic system he arranged them among themselves. In the end, Mendelejew illustrated a context between atomic weight and chemical characteristics. The element 101 "Mendelevium" was called by Mendelejew.

Before we inform you about his invention - the periodic table some information about his life and his growing passion for chemistry.

Dmitri Mendelejew was born on the 8th of February 1834 in Tobolsk, Russia. His father Ivan Pavlovich Mendelejew was a teacher and his mother Maria Dmitrievna Mendeleeva worked in a glass factory. In 1847 he attended the Gymnasium in Tobolsk and he began to study in 1850 in Saint Petersburg, Russia. He had to leave the city for some years because of tuberculosis and returned 1857. Then his career began to start because he became a professor at two Universities in Saint Petersburg. During the time Saint Petersburg developed as the center of chemistry analysis – also because of Mendeleev’s enormous influence and knowledge. He was honored by several international prices. and took, for example, part in the bureau of weights and measures and supported the population to find the first oil refinery in Russia. During this exploration he got in touch with petroleum, a liquid that is able to burn.

On the 2nd February 1907 Mendelejew's died in Saint Petersburg because of influenza at the age of 72. Now you know something about his life and that he liked to explore the “world of chemistry”. So what about his invention the periodic table of the elements? He invented the first authentic table of the elements in 1869 and published it in his book “Principles of Chemistry” (1868-1870). This table structured the elements by their atomic weight. Today, the table is structured by the atomic number because the chemist Henry Moseley discovered that you can declare the atomic numbers of elements. But all in all, the basic principle was discovered by Dimitri Mendeleev.

How is the table structured? The structure of the table consists of the periods (rows) and the groups (columns). The atomic number mounts when you move across the columns and rows. If the elements are in the same row they have got something in common. If the elements are in the same column they have the same number of electrons. At the top in the right and left corner you can find Helium (He) and Hydrogen (H). These two elements are very special and unique. Hydrogen can have the electrons of two groups. Helium is only able to have two electrons outwards.

Now, I want to tell you three facts about the periodic table.

  1. Francium is a really rarely element on our planet earth.
  2. The letter “J” is the only letter that is NOT in the table.
  3. Diamonds exist of the element Carbon, atomic number 6.