Question

a metal which reacts with acid as well as a base to form hydrogen gas

Answer 1

an amphoteric compound react with both acid and base also. for ex..Zinc

Answer 2

See the examples------

•Na+HCL=NaCl+H2

(metal)+(acid)=(salt)+(Hydrogen gas)

•Zn(s) + 2NaOH (aq) + 2H2O(l) → Na2Zn(OH)4(aq) + H2

Hope it helps to you!!