Why does no fixed place for hydrogen is mentioned in the Mendeleev per

1.	Why does no fixed place for hydrogen is mentioned in the Mendeleev periodic table
Answer» Hydrogen resembles like both the alkali metals and the halogens. Hence, it was placed in IA group VI B group and could not be given a fixed position in Mendeleev’s Periodic Table.\xa0It is so because hydrogen has 1 valence electron in its outermost shell.so according to modern periodic table, hydrogen can be arranged in halogen family i.e. group no. 17 but hydrogen does not possess the properties of halogen family. That\'s why hydrogen is given its position in the first group and first period of the modern periodic table.

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