Hydrogen is included in the reactivity series of metals because it's property of electroposivity i.e losing electron to form positive ion, is similar to that of metals, thats why we can relate it with metals!!

Hydrogen is a nonmetal and is placed above group in the periodic table because it has ns1 electron configuration like the alkali metals. However, it varies greatly from the alkali metals as it forms cations (H+) more reluctantly than the other alkalimetals. ... However, hydrogen is very different from the halogens.

It is difficult to decide where hydrogen belongs in the periodic table because of the physical properties of the element. ... This three dimensional graph of the electronegativities of the main-group elements helps us understand why it is difficult to classify hydrogen as a metal or a nonmetal.

While hydrogen is typically a gas on Earth, it can be artificially compressed and cooled to become a liquid or a solid. Even in these states, hydrogen remains a non-metal — its atoms hold on to their electrons tightly, so hydrogen conducts heat and electricity poorly.

Scientists have already made liquid metal hydrogen—the substance thought to form the interior of giant planets like Jupiter—by ramping up pressure at higher temperatures. ... As the pressure rises, the liquid quickly becomes a nonmetallic solid