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PERIODIC TABLE Name:- Brexi Joseph
Form:- 3-3
Subject:- Chemistry
Teacher:- Rochelle Joseph

TABLE OF CONTENTS

Periodic Table.......................................................................................................................................2

Dmitri Mendeleev.................................................................................................................................3

John Newlands.....................................................................................................................................4

Johann Wolfgang Döbereiner

Periodic Table

The periodic table is a chart used in chemistry that shows chemical elements in order of their atomic number.

Three of the people which contributed to the final production of the periodic table, are
Dmitri Mendeleev
John Newlands
Johann Wolfgang Döbereiner

Dmitri Mendeleev February 8, 1834 in Tobolsk, a town in Siberia, Russia. He was the youngest of a large family. The exact size of the family is a matter of dispute with sources putting the number of siblings between eleven and seventeen. February 2, 1907 (age 72) of influenza in St. Petersburg, Russia. Element 101 Md (Mendelevium) named after him. While writing his text book 'Principales of Chemistry', Mendeleev found that if you arrange the elements in order of increasing atomic mass, there chemical properties demonstrated definite trends. Which leads to his version of the periodic table, which is the back bone of the current periodic table of elements.

Mendeleev's version of the periodic table John Newlands John Alexander Reina Newlands was a British chemist. Born on the 26th of November 1837. He was the son of a Scottish Presbyterian minister and hisItalian wife. He was home schooled by his father, rather than going to a normal school. He went on to study at the Royal College of Chemistry.
Newland's was a british chemistwho noticed the repeating pattern ofwhich the elements by atomic weight where every third element had similar chemical properties. He called this the law of octoves and was a major contribution towards the development of the periodic table.

Johann Wolfgang Döbereiner Döbereiner was the son of Johann Adam Döbereiner, a farm worker who rose to become an estate manager, and Johanna Susanna Göring. He was self-educated, although his mother supervised his early instruction and in 1784 apprenticed him to an apothecary named Lutz. After three years’ service with Lutz, Döbereiner made his journeyman’s travels through Germany for five years; then he returned to Hof, married Clara Knab, and started a small business manufacturing white lead, sugar of lead, and other pigments and drugs. Almost simultaneously he began publishing articles on these chemicals in the Neues Berliner Jahrbüch für die Pharmazie, of which Adolph Ferdinand Gehlen was editor. Each of Dobereiner's triads was a group of three elements. The appearance and reactions of the elements in a triad were similar to each other. Atomic masses At this time, scientists had begun to find out the relative atomic masses of the elements. Dobereiner discovered that the relative atomic mass of the middle element in each triad was close to the average of the relative atomic masses of the other two elements. This gave other scientists a clue that relative atomic masses were important when arranging the elements.