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.
Figure 40.3 Daily Chemical Transformations Occurring in the Formation of Photochemical Smog. Generalized Reaction Scheme for Photochemical Smog Formation. This is a cyclic process that needs light and nitrogen oxides to generate oxygen atoms. Once formed, the oxygen atoms react with water to form hydroxyl radicals.