Comment on the position of hydrogen in periodic table.

Position of hydrogen

i. Hydrogen shows similarity with halogens (group VII). For example, the molecular formula of hydrogen is H2 while the molecular formulae of fluorine and chlorine are F and Cl₂, respectively.

ii. In the same way, there is a similarity in the chemical properties of hydrogen and alkali metals (group).

iii. There is a similarity in the molecular formulae of the compounds of hydrogen alkali metals (Na, K, etc.) formed with chlorine and oxygen.

iv. On considering the above properties, it cannot be decided whether the correct position of hydrogen is in the group of alkali metals (group I) or in the group of halogens (group VII).

v. So to place the hydrogen, it was placed in group 1 without any proper conclusion.