magnetic effects of electric current — Science STD 10 — Question
Gujarat BoardEnglish MediumSTD 10Sciencemagnetic effects of electric current4 Marks
Question
Discuss the formation of Ozone layer.
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Answer
→ Ozone $\left(O_3\right)$ is a molecule formed by three atoms of oxygen. While Oxygen $\left( O _2\right)$ is essential for all aerobic forms of life, Ozone is a deadly poison ous, However, at the higher levels of the atmosphere, Ozone performs an essential function. It shields the surface of the earth from ultraviolet $(uv)$ radiation. from the sun. This radiation is highly damaging to organisms. For example., it causes skin cancer in human beings.
→ Ozone at the higher levels of the atmosphere is a product of $( UV )$ radiation acting on oxygen $\left( O _2\right)$ molecule. The higher energy $UV$ radiations split apart some molecular. Oxygen $\left( O _2\right)$ into free oxygen $(O)$ atoms.
→ These free oxygen atoms then combine with the molecular oxygen to form ozone as shown in the following reaction.
(1) $O _2 \xrightarrow{ UV } O + O$
(2) $O + O _2 \rightarrow O _3$ (Ozone)
→ The amount of ozone in the atmosphere began to drop sharply in the $1980 s$. This decrease has been linked to synthetic chemicals like chlorofluorocarbons $(CFCs)$. Which are used as refrigerants and in fire extinguishers. In $1987$, the United Nations Environment Programme $(UNEP)$ succeeded in forging an agreement to freeze $CFC$ production at $1986$ levels
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