Workup. 1  Saylam G, Tanrikulu S, Dursun E, Iriz A, Eryilmaz A. A mass at fat density in the parotid gland: dermoid cyst or lipoma. B-ENT. 2009. 2  Sandborn WD, Shafer AD. A branchial cleft cyst of fourth pouch origin. 3  Thompson LD, Herrera HB, Lau SK. A Clinicopathologic Series of 685 Thyroglossal Duct Remnant Cysts.
Ozone forms readily in the stratosphere as incoming ultraviolet radiation breaks molecular oxygen (two atoms) into atomic oxygen (a single atom). In that process, oxygen absorbs much of the ultraviolet radiation and prevents it from reaching the Earthâs surface where we live.
Oxygen is a highly reactive gas that combines readily with other elements like hydrogen, carbon, and iron. Many metals react directly with oxygen in the air to form metal oxides. For example, rust is an oxide that forms when iron reacts with oxygen in the presence of water. This process is called oxidation, a term for reactions in which a substance loses electrons and become more positively charged. In this case, iron loses electrons to oxygen (Fig. 12).