Ozone A nearly colorless (but faintly blue) gaseous form of oxygen, with a characteristic odor like chlorine. Its formula is O3; its molecular weight is 48. Ozone is found in trace quantities in the Earth's atmosphere at all times, primarily in the stratosphere between heights of about 10 and 50 km (the ozonosphere or ozone shield) where its production results from photochemical processes involving ultraviolet radiation. Its maximum concentration occurs between 20 and 25 km. In the lower atmosphere, ozone is commonly formed as a product of electrical discharges through the air. |
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