Question

state the demerits of Mendeleev periodic table with reference to isotope and position of hydrogen

Answer 1

1) H2o shows similarities with halogens ( Group 7)

2)For eg. Molecular formula of hydrogen=H2

                Molecular formula of flourine, chlorine,Bromine are F2,Cl2,Br2

                  respectively

3) There is a similarities in the chemical properties of hydrogen and Alkali metals like Sodium and potassium ( Group 1)

4) Their is a similarity in the moleculer formula's of compounds of H2O and alkali metals formed with Cl2 and O2.

5)For eg. H2O, Na2o,Hcl,Nacl,etc.

6)Therefore it cannot be decided weather the correct position of hydrogen is a group of alkali or in the group of Halogens.

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