Mendeleev

Dmitri Mendeleev the father of Periodic Table

1. DIMITRI MENDELEEV Father of Periodic Table Presented by ASHA A. M.

2. Dmitri Ivanovich Mendeleev (1834 – 1907) • Russian chemist • Known as Father of Periodic table •Born in Tobolsk, Siberia • Studied and completed masters at St. Petersburg • Appointed to professorship and later to the chair in the university • He was a great teacher of his time

3. Books • The definitive two volume textbook “ Principles of Chemistry “,(1868- 1870) • “ Organic chemistry” ,1861

4. Major Contributions • Created first model of periodic table and postulated “ Periodic Law “. • Studied in the elasticity of gases • Studied the heat expansion of liquids and proposed a formula similar to Gay Lussac’s law of uniformity of expansion of gases. • Worked for first oil refinery and to transform petrol industry in Russia. • Invented pyrocolloidon,based on nitrocellulose to replace gunpowder.

5. Contd... • Studieson determining the nature of solutions. • Discussed Theory of hydration in the monograph “ Study of aqueous solution from their Specific Gravity”. • Defined critical temperature of gases as, ‘ The temperature at which cohesion and heat of vaporization become equal to zero and liquid changes to vapour irrespective of pressure and volume. • Introduced metric system in Russia.

6. Works on Periodic Table • Set out to identify the pattern in the elements. • Mendeleev wrote facts about the elements on individual paper cards. • Arranged 63 elements in the order of their atomic mass. • Found out that some elements have similar chemical and physical properties.

7. Contd... • Mendeleev’s periodic law states that “ the physical and chemical properties of elements are periodic functions of their Atomic masses.” • Each element showed properties similar to elements above and below it. • Pointed out that some atomic weights had been measured incorrectly. ( Eg., At. Mass of Beryllium was redetermined from 14 to 9)

8. • He left three blank spaces and predicted the properties of the yet undiscovered elements. Later found that his predictions hold good with their properties. ?? Eka boron 44 ?? Eka aluminium 68 ?? Eka silicon 72 Scandium Discovered in 1879 Germanium Discovered in 1886 Gallium Discovered in 1875

9. Awards • Davy medal from Royal Society of England in 1882. • Domindov prize for his book “ Organic Chemistry”. • Copley medal from the Royal Society of England in 1905.

10. Honours • Director of the Bureau of Weights and Measures (1893) • Member of Royal Swedish Academy of Sciences (1905) • The crater “Mendeleev” on the moon. Coins to memorize Mendeleev 150 year anniversary

11. • The element with atomic number 101 is named after him as “Mendeleevium” (Md). • The D.I. Mendeleev All Russian Institute of Metrology ( VNIIM ), one of the largest world centre of scientific and practical Metrology is named after him. Contd...

12. Monument to Mendeleev in St Petersburg Russia Dmitry Mendeleev sculpture in Bratislava Slovakia

13. REFERENCE The Periodic Table Book- A visual encyclopaedia of the elements; Tom Jackson NCERT Plus One chemistry text book SCERT Std.9th Chemistry text book The New Encyclopaedia Britannica, Volume 8