Ozone. Prevents UV-B radiation from reaching the Earth Found in stratosphere When O 2 absorbs UV radiation it breaks down to O + O atoms Free oxygen reacts with O 2 to produce O 3 O 3 absorbs UV radiation and breaks down to O 2 + O
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Prevents UV-B radiation from reaching the Earth
Found in stratosphere
When O2 absorbs UV radiation it breaks down to O + O atoms
Free oxygen reacts with O2 to produce O3
O3 absorbs UV radiation and breaks down to O2 + O
This back & forth exchange, shields the Earth from the UV radiation
Chlorofluorocarbons are inert –un-reactive, odorless , non-toxic, colorless, nonflammable, noncorrosive – and possess desirable properties as refrigerants, solvents, propellants.
Considered a dream chemical w/ no adverse human or environmental effects
PROBLEM AROSE WITH ITS
Un-reactive in the troposphere, but when they reach the stratosphere they react with UV radiation
UV radiation allows for the breaking off of a chlorine atom.This chlorine atom reacts with ozone
CFCl3 + UV ----- Cl + CFCl2
Cl + O3 - ClO + O2 repeats
ClO + O - Cl + O2 many times
UV-A has lowest energy, lowest potential for harming life. Not absorbed by the ozone layer
UV-B harmful to life, absorbed by the ozone layer, destruction of stratospheric ozone allows UV-B to pass through
UV-C highest energy. Breaks down oxygen molecules. Absorbed by oxygen in the atmosphere.