Nitric acid Nitric acid can oxidize non-active metals such as copper and silver. With these non-active or less electropositive metals the products depend on temperature and the acid concentration. For example, copper reacts with dilute nitric acid at ambient temperatures with a 3:8 stoichiometry: The nitric oxide produced may react with atmospheric oxygen to give nitrogen dioxide. With more concentrated nitric acid, nitrogen dioxide is produced directly in a reaction with 1:4 stoichiometry: Upon reaction with nitric acid, most metals give the corresponding nitrates. Some metalloids and metals give the oxides; for instance, Sn, As, Sb, and Ti are oxidized into SnO,
Metal some are essential in trace amounts. All other metals are light metals. In chemistry, the term "base metal" is used informally to refer to a metal that is easily oxidized or corroded, such as reacting easily with dilute hydrochloric acid (HCl) to form a metal chloride and hydrogen. Examples include iron, nickel, lead and zinc. Copper is considered a base metal as it is oxidized relatively easily, although it does not react with HCl. The term noble metal is commonly used in opposition to "base metal". Noble metals are resistant to corrosion or oxidation, unlike most base metals. They tend