Search results
Results From The WOW.Com Content Network
Essentially all UV-C (100–280 nm) is blocked by dioxygen (from 100–200 nm) or else by ozone (200–280 nm) in the atmosphere. The shorter portion of the UV-C band and the more energetic UV above this band causes the formation of the ozone layer, when single oxygen atoms produced by UV photolysis of dioxygen (below 240 nm) react with more ...
The amount of UV radiation produced by the Sun means that the Earth would not be able to sustain life on dry land if most of that light were not filtered out by the atmosphere. [1] More energetic, shorter-wavelength "extreme" UV below 121 nm ionizes air so strongly that it is absorbed before it reaches the ground. [2]
Ozone's effect on mid-range UV-B rays is illustrated by its effect on UV-B at 290 nm, which has a radiation intensity 350 million times as powerful at the top of the atmosphere as at the surface. Nevertheless, enough of UV-B radiation at similar frequency reaches the ground to cause some sunburn, and these same wavelengths are also among those ...
UV is the lowest energy range energetic enough to ionize atoms, separating electrons from them, and thus causing chemical reactions. UV, X-rays, and gamma rays are thus collectively called ionizing radiation; exposure to them can damage living tissue. UV can also cause substances to glow with visible light; this is called fluorescence. UV ...
The optical atmospheric window is the optical portion of the electromagnetic spectrum that passes through the Earth's atmosphere, excluding its infrared part; [10] although, as mentioned before, the optical spectrum also includes the IR spectrum and thus the optical window could include the infrared window (8 – 14 μm), the latter is ...
Oxygen and ozone continuously interconverted. Solar UV breaks down oxygen; molecular and atomic oxygen combine to form Ozone. 3. Ozone is lost by reaction with atomic oxygen (plus other trace atoms). The ozone–oxygen cycle is the process by which ozone is continually regenerated in Earth's stratosphere, converting ultraviolet radiation (UV ...
Ultraviolet rays interact with these bonds to form free radicals, which then react further with oxygen in the atmosphere, producing carbonyl groups in the main chain. The exposed surfaces of products may then discolour and crack, and in extreme cases, complete product disintegration can occur.
It is formed by reaction of intact O 2 with atomic oxygen produced when UV radiation in the upper atmosphere splits O 2. [5] Ozone absorbs strongly in the ultraviolet and in the stratosphere functions as a shield for the biosphere against mutagenic and other damaging effects of solar UV radiation (see ozone layer). [5]