Chemistry

Periodic table    part-2 (E):   Telluric Helix : A three dimensional periodic table given by De-chan-chortois.  This table is also known as tellurix helix.  (F):  Mendeleev's periodic table: Mendeleev's   periodic law - The physical and chemical properties of element are the periodic function of their atomic wt. It is based on atomic weight. 63 element was known noble gases were not discovered. He was the first scientist to classify the elements in a systematic manner that is in horizontal row and in vertical columns. Horizontal rows are called periods and there was 7 periods in Mendeleev periodic table Vertical columns are called groups and there were eight groups in Mendeleev periodic table. Each group of 28 is divided into a and b subgroups a Sub group elements are called Normal elements and B Sub group elements are called transition elements. The metal belonging to the same group exhibit similar properties.  Demerits of Mendeleev's periodic table: Position of hydrogen...

Periodic table  Part.1 (A)   Prouts concept  Is simply asm.com the elements are made up of hydrogen so we can say that  .. Atomic weight of element= n×(Atomic weight.of one hydrogen atom) Where n= no. of hydrogen atom= 123 Drawbacks or limitations: Letter on elements discovered having atomic weight infections like chlorine atomic weight 35.5, Strontium atomic weight 87.5 and proud could not explain why this weights are instructions beasar this is a drawback. (B).   Dobereiner trait rule He made groups of three elements having similar chemical properties  In Dobereiner trait, atomic weight of middle element is equal to the average atomic weight of first and third element. Eg.   Cl               Br.            I          35.5           80.0.         127                  35.5+127/2 =  81.25 (C) Newland law of octaves He arrange the element in increasing order of their atomic mass and observe that properties of every 8th element was similar to the first one like in the case of musical vowe...