Today we will be studying chapter number: six, that is physical and chemical changes, part three, so children in my last two parts we have studied about what other chemical changes: Music, Music, which are the chemical Music. Now let us see more about this chapter. Yes, a practical shape. What is protective shape? Let us see the ozone layer is in our atmosphere. Okay, so on the earth layer there are four layers: okay, in there, the ozone layer is present in the atmosphere, so it protects us from the harmful ultraviolet radiations which come from Applause. Ozone absorbs this radiation and brings down to oxygen. Oxygen is different from ozone. If ultraviolet radiation were not absorbed by ozone, it would reach the earths surface and cause harm to us. Music depletion. Music. The ozone layer has been radiations, are very harmful for our body for our skin. Okay, now ozone act has a natural shape against this radiation. Now the next topic is 6.3 rusting Music due to the moisture which is present in our atmosphere. Okay, so what is containing that? And what does it affect to the iron? Those colors takes Music Music about it. This is one change that affects island articles and slowly destroys them. Since iron is used in making bridges, ships, cars, trucks, truck bodies Music, how much dangerous it would be in economic way that it is giving a huge loss where it is yet rusted. The process of rusting can be really presented by the following reaction: iron, iron symbol, fp oxygen, decimal gap, o so oxygen from the egg from the air plus water.

That is h2o. What does it give rust? Music, both oxygen and water? All water vapor is essential. Okay – and they both when they are there and comes in in Music, have been observed now resting of either prevent iron particles from coming in contact with oxygen or water, or both one simple days for that food of pain, to prevent rusting, okay, regular intervals with one Year or two year in that way, we should paint our iron orchid so that they do not get rusted and do not come in contact with any of the moisture or the Music is Music. Music. We use in our homes to get water are galvanized to prevent rusting for using the for pipes. Okay, it is used that is galvanized pipe Music, Music above Music due to the galvanization process. Okay, that is the coating of the sink. Let us see what happens. Moreover, the water of the sea contains many salts. The salt water makes the process of rust formation very fast. Ships suffer a lot of damage from rustic in spite of being painted, and also it is having getting rusted so much so that the refraction of ships iron Music is made by mixing iron with carbon and metals. Okay, so seriously. The ss gold, then that is c, is made by mixing iron with carbon and metals like chromium, Music, Music, Music. In this manner, the shape of the crystals cannot be seen. Clearly, however, last whistles of pure substances can be formed from their solution.

The process is called crystallization, Music. Okay, so what is? Is Music, Music Applause? It now continue adding powder Music, foreign Music, allow it to cool Music, okay children. So this was all about chapter number, six, physical and radical changes. I will be sending you my next video in which the exercise will be there. Please do write it and your science is more important. Then stay home stay safe. Thank you.

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