Oxygen is chemically reactive. With the exception of noble gases and relatively unreactive metallic elements-such as gold, platinum, and silver-most elements are capable of reacting with oxygen.
All chemical reactions involving combustion or slow oxidation-that is, reactions in which a substance combines with oxygen-proceed very rapidly and vigorously in an atmosphere of pure oxygen, simultaneously releasing a substantial amount of heat. For instance, if a smoldering (but not yet burning) wooden splint is placed into a container filled with oxygen, it will burst into a bright flame. Similarly, if a piece of sulfur-which burns with a white flame in air-is introduced into a container of oxygen, it will suddenly ignite and burn with a violet flame. Aside from its inability to react with noble gases such as helium, neon, and argon, as well as certain unreactive metals, oxygen is capable of combining with all other metallic and non-metallic elements to form oxides.
