What are the two forms of oxygen found in the atmosphere ?

Oxygen found in the atmosphere exist in 2 forms,

1) Elemental: - this form of oxygen exist as di-oxygen molecule or O2. It forms 21% of the total air present on the earth. This form is present in the lower part of atmosphere where we live, it is non-poisonous and we inhale this form only. Plants also consume this form of oxygen.


2) Ozone: - this form of oxygen is formed by the combination of 3 oxygen molecule, O3. It is present in the stratosphere region of earth’s atmosphere and forms a protective layer around earth to protect us from the harmful U.V radiations coming from the sun. It is toxic and highly unstable, in the stratosphere also it keeps on breaking and forming in the presence of sunlight.



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