The correct answer is Element 'A' is a metal: gas evolved is hydrogen.Concept:Chemical reaction: It is a process in which one or more substances, the reactants, are converted to one or more different substances, the products.A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products.Explanation:Metals react with dilute acids to give salt and hydrogen gas. When element 'A' reacts with dilute hydrochloric acid, bubbles of a colourless gas evolve that burn with a pop sound.The gas is hydrogen, which is inflammable because it will burn on bringing a lit matchstick near it.So, element A is a metal.Additional Information Chemical properties of metals:The metal reacts with oxygen to form metal oxide.The metal reacts with an acid to form a salt and hydrogen gas. Metals react with water to form oxides or hydroxides.Metals do not react with alkalis.