Mercury dissolves to form amalgams with gold, zinc and many other metals. Because iron is an exception, iron flasks have been traditionally used to trade mercury. Other metals that do not form amalgams with mercury include tantalum, tungsten and platinum. When heated, mercury also reacts with oxygen in air to form mercury oxide, which then can be decomposed by further heating to higher temperatures.[6]
Since it is below hydrogen in the reactivity series of metals, mercury does not react with most acids, such as dilute sulfuric acid, though oxidizing acids such as concentrated sulfuric acid and nitric acid or aqua regia dissolve it to give sulfate, nitrate, and chloride salts. Like silver, mercury reacts with atmospheric hydrogen sulfide. Mercury even reacts with solid sulfur flakes, which are used in mercury spill kits to absorb mercury vapors (spill kits also use activated charcoal and powdered zinc).[6]
Some important mercury salts include:
Mercury(I) chloride (calomel) is sometimes still used in medicine, acousto-optical filters and as a standard in electrochemistry;[7]
Mercury(II) chloride is a very corrosive, easily sublimating and poisonous substance;[3]
Mercury fulminate, (a detonator widely used in explosives);[3]
Mercury(II) oxide, the main oxide of mercury;
Mercury(II) sulfide (found naturally as the ore cinnabar, or vermilion which is a high-grade paint pigment);[3]
Mercury(II) selenide, Mercury(II) telluride, Mercury cadmium telluride and mercury zinc telluride are semiconductors and infrared detector materials.[8]