Question

what is the reason behind the controversial position of hydrogen in the modern periodic table?

Answer 1

according to electronic configuration its 1s1 so it should fall in the first column that is alkaline earth metals
like alkali metals hydrogen also looses its only one electron to form hydrogen ion ,H(+)
combination with non-metals:-like alkali metals hydrogen combines with non-metals such as oxygen and sulphur forming their oxides and sulphides


hydrogen also resembles with its properties with the halogen group elements that is group 17
high electronegative character of halogens and Hydrogen,
high ionization energy of hydrogen comparable to halogens
Etc

as result now days they keep hydrogen at the center of the periodic table