 In this activity we will explore rusting of iron and for this activity you need a bunch of stuff to start off with you need some plastic tubes, three plastic tubes or test tubes. You need three iron nails. You also need some baking soda. Here is some boiled water and you need a dropper with with some oil in it. So we will start by adding some baking soda in one of the plastic tubes. All right now we will add some boiled water in the second plastic tube and in the third tube we have normal water, normal room temperature water. All right now I will drop iron nails in each of these tubes like this and in the second tube where I added some boiled water I will add a layer of oil on top of it. All right now I will close all of these tubes. Okay now we have these three plastic tubes with iron nails in it but what is inside these tubes apart from the iron nails is different. Let's talk about that for a moment. So in the first plastic tube the one on the left we have baking soda. Now what baking soda does is baking soda absorbs all the moisture in the air around it which means it absorbs the water molecules in the air around it. In fact it's called a dehumidifying agent which means it absorbs all the moisture that is present in the air around it and in the tube in the middle we have boiled water and a layer of oil on top of it. Now when we boil water it removes all the oxygen in it. Boiled water has no dissolved oxygen and a layer of oil is kept on top which is to prevent any oxygen present in the air to dissolve in the water. The layer of oil is preventing any oxygen to enter in the boiled water. And in the third tube the one on the right it has normal water. There is nothing like baking soda there is no boiled water it just has normal water in it. Now at this point I wanted to predict which iron nail do you think will rust out of these three. We will leave this setup for around five six days and we'll come back to it after five six days and think about it which which iron nail do you think will rust. Okay so here we are after five days I'll take out the iron nails now. Here is the one in the baking soda it's difficult to take it out okay here it is. Here is the one in the boiled water with a layer of oil on top of it and here is the one in normal room temperature water. Now let's look at them closely. So this is this is the first one which was kept in baking soda. Now this iron nail looks okay right it's still shiny we don't see any coating on top of it. Nothing seems to have changed for this iron nail that was kept in the baking soda. Have a look at it from a different angle. It looks it looks like any other any other iron nail right. So we can say that no rusting really happened here. Now here is the second one that was kept in boiled water with with a layer on top of it. Even this iron nail looks okay right there is no coating on top of it. So in in this case also we can say that there is no rusting. No rusting happened in the second tube as well. Now here is the third one look look at this one the one that was kept in normal room temperature water. We see we see a reddish brownish coating on top of it right. Let's let's try and look at it from a different angle. I hope you can see we can see some coating on top of it. Particularly in the middle reddish brownish coating on top of it. So turns out this iron nail that was kept in normal room temperature water this actually underwent rusting. This iron nail rusted. Now we can think about why that happened. So in the first plastic tube the one on the left which had baking soda in it baking soda absorbed all the moisture water in the air around it. And the iron nail did not rust. In the second case there was no oxygen. Boiled water had no oxygen dissolved in it and the layer of oil prevented any oxygen to enter into the water. But in the third case both water moisture in the air and and there was oxygen present in the third plastic tube the one on the right. So from this we can say that in order for something to rust there needs to be two things present. One is water and the other is oxygen. And that's why iron nail rusted in the third case because there was both of these things present. There was water of course it was dipped in water and also there was moisture in the air around of it. And there was also oxygen present in the air around of it. So that's why we see a reddish brownish coating of rust on top of the third iron nail. And that coating in fact has a name it's called iron oxide. So when iron reacts with oxygen in the presence of water iron oxide forms which is the chemical name or the scientific name for rust.