The hydrogen gas is neither an acid nor an base, because now it is H+H =H2 , its is not an proton donor and electronic acceptor any more.

Is H a base or acid?

Let’s look at the breakup of molecules in aqueous (water-based) solutions one more time for good measure. Acids are compounds that dissociate (break) into hydrogen (H+) ions and another compound when placed in an aqueous solution.

Is anything with H an acid?

All acids contain hydrogen. Acids dissociate in water to produce hydrogen ions. Basically, acids are just ionic compounds that contain hydrogen. A strong acid completely ionizes, breaking down into positive hydrogen ions and negatively charged ions.