Answer:
a) At about 15 to 35 km from the Earth
b) It helps to absorb most of the ultraviolet rays from the sun, that is otherwise too dangerous here on Earth.
c) The depletion of the ozone layer is due to free radical catalysts, like nitric oxide (NO), nitrous oxide (N2O), hydroxyl (OH), but majorly due to atomic chlorine (Cl), and atomic bromine (Br) finding their way up to the the ozone layer.
d) The refrigeration processes and the aerosol aligned industrial processes, are the major culprits.
Explanation:
a) The ozone layer is lies in the lower portion of the stratosphere, from an height of about 15 to 35 kilometers from the surface of the Earth.
b) The ozone layer contains a large portion of ozone, a molecule of oxygen containing three oxygen atom bonded together. This ozone is created at this level by the action of ultraviolet radiation on an ordinary oxygen molecule, splitting it into two oxygen atom. Each of this oxygen atom then proceed to combine with another ordinary oxygen molecule, to form an ozone molecule. The ozone at this layer absorbs a large portion of the ultraviolet radiation from the sun.
c) The depletion of the ozone layer is due to the presence of some radical, that are able to survive up to the level of the ozone layer. At this level, ultraviolet radiation causes these these radicals to dissociate to give free bromine and chlorine mostly. This chlorine and bromine molecules breaks down the ozone molecules.
d) The various industrial processes includes refrigeration, and the aerosol industries that majorly releases the chlorofluorocarbons (CFCs) and bromofluorocarbons, which are the main culprits of ozone depletion.
