• # question_answer An element reacts with hydrogen to form a compound A which on treatment with water liberates hydrogen gas. The element can be A) Nitrogen B) Chlorine C) Selenium D) Calcium

$Ca+{{H}_{2}}\to Ca{{H}_{2}}\xrightarrow{2{{H}_{2}}O}Ca{{(OH)}_{2}}+2{{H}_{2}}$