Give reasons why hydrogen resembles alkali metals?
Hydrogen is said to be an analogous element when its position in the periodic table is considered. This is because it shares its properties both with alkali metals as well as with halogens in the field of sharing or gaining electrons or in other words it has its electronic configuration similar to these. That is why its position in the periodic table is not justified.
The electronic configuration of hydrogen (1s1) is similar to that of alkali metals (ns1) which shows that only one electron is present in their valence shell. So if they lose that single electron, a uni-positive ion would be formed.