THE ozone layer is composed of ozone gas (whose molecular formula is O3) and is located in a region of the atmosphere called the stratosphere, which lies between 20 km and 35 km from the Earth's surface.
Schematic representation of all layers that make up the atmosphere
the existence of ozone layer helps in the maintenance of life on our planet, as it manages to filter around 95% of ultraviolet rays (UV) coming from the Sun, preventing most of these rays from reaching the Earth's surface.
A negative point in relation to ozone gas is that, in the troposphere (atmospheric layer closest to the earth's surface), it is also present, but in smaller quantities, and participates in the smog photochemical, that is, it participates in a phenomenon of atmospheric pollution.
ozone formation
The amount of O3 present in the ozone layer is constantly modified because the ultraviolet rays, upon reaching the layer, promote the separation of one of the oxygens from the ozone, forming more oxygen gas.
O3(g) → The2(g) + O(g)
In addition to ozone degradation, ultraviolet radiation also breaks the bond between the oxygens of some oxygen gas molecules, as in the following equation:
O2(g) → 2O(g)
Then, however, each free oxygen interacts with an oxygen gas molecule, forming an ozone gas molecule (O3), as in the following equation:
O+O2(g) → The3(g)
Thus, the amount of ozone gas in the layer is constantly changing naturally.
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Importance of the ozone layer
The existence of the ozone layer in the stratosphere is essential, as it prevents much of the ultraviolet radiation from reaching the earth's surface. When ultraviolet radiation reaches the Earth's surface, it can trigger various damages to various living beings, namely:
Skin cancer development;
Increased frequency of activations of herpes virus replication in individuals who have contracted it, developing the characteristic lesions of the disease;
Blindness caused by increased cataract in individuals with a tendency to develop it;
Increased temperature of the planet (global warming), since a greater number of ultraviolet rays reach the Earth's surface, increasing heat retention.
Substances that damage the ozone layer
Among the chemical substances that end up reacting and degrading ozone are:
Nitric Oxide (NO): substance produced from burning fossil fuels;
Nitrous oxide (N2O): substance eliminated by vehicles and chemical industries;
carbon dioxide (CO2): substance usually produced in chemical reactions of complete combustion;
Chlorofluorocarbons (CFCs): substances widely used as propellants in aerosol products (such as spray deodorant), in the production of plastic materials and in refrigeration equipment (such as refrigerators).
These substances, in general, damage the ozone layer because, when affected by ultraviolet radiation, especially CFCs, they have its molecules decompose, causing its free atoms to react with the ozone molecule, turning it into an oxygen gas molecule (O2). This occurrence reduces the concentration of ozone and the filtering of ultraviolet rays.
By Me. Diogo Lopes Dias
Would you like to reference this text in a school or academic work? Look:
DAYS, Diogo Lopes. "What is the ozone layer?"; Brazil School. Available in: https://brasilescola.uol.com.br/o-que-e/quimica/o-que-e-camada-ozonio.htm. Accessed on June 27, 2021.
Chemistry
Allotropic form of oxygen, unstable gas, diamagnetic, highly reactive, extremely strong oxidizer, toxic element, photochemical action of ultraviolet rays, ozone layer, medicinal ozone, tropospheric ozone, nitrous oxide, compounds organic
Chemistry
Ozone coating that surrounds the Earth, why the ozone layer is destroyed, energy release, chlorofluorocarbons, photodecomposition of chlorofluorocarbon molecules, ozone depletion catalyst, atom of chlorine, ultraviolet rays
