Dmitri Mendeleev

Periodic Table of Elements

His Life

Dmitri Mendeleev was born at Tobolsk, Siberia in 1834. He studied science at St. Petersburg and graduated in 1856. In 1863 Mendeleev was appointed to a professorship and in succeeded to the Chair in the University. The Russian chemist and science historian L.A. Tchugayev has characterized him as “a chemist of genius, first-class physicist, a fruitful researcher in the fields of hydrodynamics, meteorology, geology, certain branches of chemical technology and other disciplines adjacent to chemistry and physics, a thorough expert of chemical industry and industry in general, and an original thinker in the field of economy.

His greatest accomplishment, however, was the stating of the Periodic Law and the development of the Periodic Table. From early in his career, he felt that there was some type of order to the elements, and he spent more than thirteen years of his life collecting data and assembling the concept, initially with the idea of resolving some of the disorder in the field for his students.


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Best Known For

Dmitri Mendeleev was an irascible Russian chemist who is famous for his work in developing the periodic table of elements. Mendeleev started working on the periodic table in 1869 where he grouped elements according to their atomic weight in an ascending order.


What is the Periodic Table of Elements?

Dmitri Mendeleev was the first scientist to create a periodic table of the elements similar to the one we use today. You can see Mendeleev's original table (1869). This table showed that when the elements were ordered by increasing atomic weight, a pattern appeared where properties of the elements repeated periodically. This periodic table is a chart that groups the elements according to their similar properties. Mendeleev's table didn't have many elements. He had question marks and spaces between elements where he predicted undiscovered elements would fit.
Discovering Elements
The number of protons determines the atomic number of an element, which is its number on the periodic table. There aren't any skipped atomic numbers on the modern periodic table because new elements are synthesized rather than discovered. The placement of these new elements on the periodic table can be used to help predict the element's properties.
Element Properties and Trends
The periodic table helps predict some properties of the elements compared to each other. Atom size decreases as you move from left to right across the table and increases as you move down a column. Energy required to remove an electron from an atom increases as you move from left to right and decreases as you move down a column. The ability to form a chemical bond increases as you move from left to right and decreases as you move down a column.