Periodic Table

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on December 03, 2019

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gallery Periodic table images

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History of periodic table | Lavoisier Classification, Prout's Hypothesis, Dobereiner trade, Newland octave rule, Lothar Mayer's Curve, Mendeleev's periodic table

1.0 Introduction : The arrangement of all the known elements according to their properties in such a way that the elements which similar properties are grouped together in a tabular form. Development of periodic table (A) Lavoisier Classification : (i) Lavoisier classified the elements simply in metals. Metals are the one which have the tendency of gaining the electrons. Na → Na⁺ + e ‐ and K → K⁺ + e- Non-metals are the one which have the tendency of gaining the electrons. F + e- → F⁻ and Cl + e ⁻→ Cl ⁻ (ii) Drawback or limitation : As the number of elements increases, this classification become insufficient for the study of elements. There are few elements which have the properties of both meals as well as non-metals and they are called metalloids. Lavoisier could not decide where yo place the metalloids. (B) Prout's Hypothesis : He simply assumed that all the elements are made up of hydrogen, so we can say that Atomic weight of elements = n ×

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