2.Ozone :                                      

        Ozone is one of the most famous products of complete oxidation in our atmosphere. 

        The ozone molecule consists of three oxygen atoms. This gas result from lightning, and most of it remains in the upper layers of the atmosphere. It acts as a barrier to prevent some the the ultra-violet rays coming from the sun from reaching living organisms. Ozone therefore protects these organisms against burning and poisoning.

        As a result of using the ferion compounds for making splashers, refrigerators and air conditioners; it spreads in air and concentrates at the poles of the earth, as a result of the air whirlpools, which leads to untying and decay of ozone gas (forming the ozone hole) and leads to spread of the harmful universal rays and the ultra-violet rays as well.

        The ozone gas might be formed in electrical transformers, and electrical power station, where it harms the eye and lungs.