Notes, Exercises, Videos, Tests and Things to Remember on Ozone Layer
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When three atoms of oxygen combine together then the resulting molecule is called ozone. Its molecular formula is O3 and is pale blue color. It is formed naturally due to action of uv on oxygen. The ozone layer shields the earth from the harmful ultraviolet radiation. The ozone layer not only absorbs ultraviolet radiation but also the radiation of wavelength less than 3x10-7 m.
The layer of ozone present in Stratosphere which Protect earth from direct ultraviolet rays of the sun is called ozone layer or ozonosphere. When an oxygen molecule absorbs high energy of solar radiation, it dissociates into nascent oxygen. The nascent oxygen then combines with oxygen and ozone molecule is formed.
When atmospheric oxygen (O2) is influenced by ultraviolet rays of the sun it disassociates in to nascent oxygen. The nascent oxygen combines with Oxygen to form ozone. When ultra violet rays having wavelength less than 340 nm are absorbed by ozone they disassociate in to O2 and nascent (O). The nascent oxygen forms oxygen molecule latter.
The rate of formation and destruction is equal naturally. But because of human activity the rate of destruction of ozone is increasing so the thickness of ozone layer is thinning day by day. This process is called ozone layer depletion.
There are various agents that help to destroy ozone molecule and convert them in to oxygen gas. Some of the common sources of ozone layer depletion are.
If we use chemical fertilizers in farm excessively then unused part of fertilizers will be converted into various toxic oxides by the action of soil bacteria which will deplete ozone layer by reacting with ozone.
Fires releasing from woods contain chlorine-containing compounds. Some of these can reach the ozone layer, and cause ozone depletion. Wildfires consume oxygen, and destroy oxygen producers. Ozone depends on oxygen being present to be made. Wildfires alter the surface resistance of the Earth's surface (Hotter/more absorptive), and left water vapor both of these tend to drive more water vapor into the ozone layer, where it to cause ozone depletion.
Due to ozone layer depletion, ultra violet rays of the sun may fall directly on the earth's surface which may cause skin inflammation, different types of cancer, loss of immunity. It also effect DNA replication by forming dimers.
Plants are also affected by ozone depletion. It reduces forest and decrease the crop yielding. Various species of plants may extinct. It reduces of rate of photosynthesis and water use efficiency of plants.
Ultravlet rays of the sun also affect fertility of animals. Eggs of aquatic animals and amphibian die to ozone layer depletion. It causes adverse effect on layer depletion. It causes effect on their population. The ozone layer depletion can cause many types of cancer to other animals also.
The main Cause of Ozone layer depletion Are chlorofluorocarbons (CFCÃ¢â‚¬â„¢s) and oxides of nitrogen. These gases are also greenhouse gases. Due to over greenhouse effect the temperature of the earth increases which cause global warming. It is believed that if temperature of the earth continues to increases in the present ratio the day is not so far when the oceans will engulf numbers of islands.
The sun's radiation decomposes oxygen (O2) gas to form oxygen atoms (O). When oxygen atom combines with the molecule of oxygen, ozone (O3) is formed. O2 → O+O O2+O → O3
Ozone layer prevents most of the harmful radiation from the sun from entering the earth's atmosphere. As a result, organisms survive from its bad effect and aquatic and terrestrial ecosystems are preserved.
The effects of depletion of ozone layer in aquatic/amphibian animals are:
a. The rate of reproduction decreases.
b. The eggs and larvae die.
Due to the chemicals like chlorofluorocarbon, chloroform, carbon tetrachloride, methyl bromide, etc. the ozone layer is destroyed. This destruction of ozone layer is called ozone layer depletion. Due to ozone layer depletion, the ultraviolet rays from the sun will enter the earth's atmosphere and causes the following effects: a. Effect on health b. Effects on plants c. Increase in temperature.
Ozone layer can be protected in the following ways: a. Avoiding the machines and apparatus that use chlorofluorocarbon. b. Producing other less harmful gases than chlorofluorocarbon.
It is better not to overuse Refrigerator with CFC because CFC is considered as the major cause for ozone layer depletion. If ozone layer is depleted, people may suffer from skin cancer due to UV rays that are reflected by ozone layer under normal condition.
The effects due to depletion of ozone layer to the health and environment are:
i. Effects on health: Ultraviolet radiation causes cataract disease to human eyes, increases the probability of skin cancer, skin crack and sunburn. The human immune system is also weakened.
ii. Effects on environment: As more ultraviolet radiation enters the earth, the heat accumulates more and greenhouse effect increases causing an increase in the earth's temperature. The weather becomes abnormal and ice cap melts increasing the sea level.
The molecular formula of ozone is ______.
The color of ozone is ______.
Ozone layer is found between ______.
19-48 km in the troposphere
19-48 km in the mesosphere
50-80 km in the strastosphere
19-48 km in the strastosphere
Ozone is made up of ______.
three oxygen atoms
three hydrogen atoms
six oxygen atoms
four oxygen atoms