 associated with this atom is assumed to be if all the bonds associated with this atom is assumed to be Electrovalent, Electrovalent bond, Any bond, Covalent bond, all the bonds associated with it is assumed to be Electrovalent bond, I need. See there are two types of bond we have, which the average bonds to form a bond again. The one is Covalent bond where we have a sharing of electron, the electron gets shared between the two atoms. Any bond that happens, the more electronegative element will have the electron, suppose I take an example. If you see the electron, sodium has, what is the common number of sodium? 11. 11, right. So, we will write it down you know, 2, 8 and 1, right for sodium, what about sodium? 17. So, in the last shell it has 7 electrons, 17, right, 17 to 2, 8 and 7. So, you see this configuration, to gain octet, octet you know what is octet? Yes sir. Octomershell should have 8 electrons. So, to gain this atom, sodium octet, it requires 8 electrons in the octomershell. So, it is very difficult to accept 7 electrons and it is easier to lose this one electron, so that it will have 8 electrons in the octomershell. So, it has tendency to lose electron, but it has tendency to accept the electron, right, 7 electrons. So, what happens the electron of sodium, suppose this dot is the electron of sodium we have and it has 7 electrons of chlorine is this, 1, 2, 3, 4, 5, 6 and 7, ok. So, what happens this, anything donates its electron to this chlorine, right and we have the positive charge from it, correct. Since chlorine extracts one electron from the other atom, so it has one extra electron, so it has one negative charge. Now, we have this positive and negative charge, so we have attraction and positive and negative charge, this is attraction we call it as electrostatic attraction. Attraction is similar to the attraction we have seen between the two opposite charges, right. So, it is a charge of species, positive charge of species, it is also negative charge of species, so we have attraction between these two and that is why in presence C L mines are bonded together. This kind of bond because it has bonded, binding bond or electro, well in bond due to electrostatic force of attraction, right. So, this is binding bond and that is what the you know the definition of its oxidation number is. If all the atoms, all the bonds between the two atoms is assumed to be what, electrostatic, right. But it is electrostatic that the charge of the species is said to be what, oxidation number on that particular atom. Like in case of A is here, oxidation number of sodium is what, plus 1, for chlorine is what, minus 1. Similarly, it will be M T C I 2, right. So, charge and coating is what, minus and here it is, plus 2. So, oxidation number of ionization is plus 2, protein is minus 1, right. So, this is what oxidation number is, we assume all the bonds to be electrostatic. Apart from this, I have discussed covalent bond, electrovalent bond that is ionic and one more we have to call it as what, coordinate bond, coordinate bond. We will discuss that also. Again all these things we will discuss in chemical bond lecture. I am giving you a brief idea so that you can understand the things, right. Write down next line, this example also you write down these examples, N A plus and C L minus and M G C. Now, how to assign oxidation number, we have two three rules into this. First we will write down, write down first to assign oxidation number. These rules actually you have to analyze. First case to write down, in case of ionic compound, in case of ionic compound write down, in this case the charge on an atom, the charge on an atom is taken as the oxidation number. The charge on an atom is taken as oxidation number. Example is this one, N A C L and M G C L to be connected, plus 2, minus 1, plus 1, minus 1. Okay, N A C L and M G C L. Second case, write down in case of covalent bond, in case of covalent bond, covalent bond, the charge is given to less electronegative. In case of covalent bond, the plus 1 charge is given to less electronegative element, minus 1 charge is given to more electronegative element. So, basically plus 1 electronegative element, minus electronegative element. Yes, electronegative element, which one is electronegative element. For example, you see H C L. In H C L, protein is more electronegative element. So, we will have C L minus and H plus. This is the oxidation number of protein and the oxidation number of carbon. The first one is C H 4. The second one is C H 3 C L. Third one is C H 2 C L 2, C H C L 3 and C C L 4, oxidation number of carbon. You know this method because you have X, so it is X this plus 1. So, what we will write X? Because C H 4 is neutral, there is no charge in this case. Similarly, here also plus 2, net charge and write on the right hand side. What is the support command? Minus 2. Minus 2 because of the charge. Carbon is this molecule, so there is no charge in this molecule. That is why it is easier. X is what we have to see. Which is structure also we have to see. For C H 4 there is no charge. So, for this particular bond, the carbon we have got minus 1 charge 1 and plus 1 charge in this case. Yes or no? Similarly, for this one, again minus 1 charge. So, what is the total charge? This total value is minus 1 plus 1. So, this actually gives you the real picture. Here this value is the average. This X value or this method gives you the average. Since we have only the structure is C level 1, O and C level 1. It is a linear molecule. All these structures shape geometry. If the carbon is attached with one hydrogen this way, one oxygen this way. So, the linear molecule, the bottom oxygen should be 180. This is not linear. This way, one hydrogen is this way, another hydrogen is this way. So, we have a triangle like this carbon. And with this carbon, this geometry is called this geometry. And that geometry in shape is not required here. It is not required in the last one actually. So, the geometry in shape we will discuss in the upcoming video. So, carbon if you write like this is not linear. The bottom angle is not 180. The linear molecule should be straight. So, you see the carbon oxygen is more than 180 again. So, what is the charge in this oxygen? Minus 2. We will give minus 2 because we have two points here. Like 1 points minus 1, 2 points minus 2. Here also it is minus 2. So, it is minus 2 to this one is plus 2 to this one is plus 2 to this one is what? Plus 2 is plus 2 to this one. Okay. Sulfurized structure. It is not that difficult but again like I said structure and everything we will discuss in chemical bonding after that chapter you will understand all these things. Okay. Again the sulfur atom is S3 3 hybridized, joint is S3 3 hybridized. So, I have drawn the same structure like this. Okay. Now the sulfur atom, whenever oxygen is bonded with what I said oxygen is bonded with one single bond it will have one negative charge on it. Right. So, since we have two negative, you cannot write down this. When you make this bond, single bond which you have to put one negative charge here which is not possible because there is not negative. The three negative charge is not there. Chemical bonding chapter. Okay. So, for now you just write it down. Sulfur ion is this. Right. So, you see S double bond O because of this double bond what is the charge on the sulfur? On the sulfur. Because minus. Plus 2, say oxygen is more electro negative. Yeah. Here because of this double bond the charge on sulfur is what? Plus 2. Plus 2. Because of this? Plus 2. I am plus 2. This is? Minus. Plus 1. Plus 1. And this is? Plus 1. Plus 1. Plus 1. Plus 1. Plus 1. Plus 1. Plus 1. Plus 1. Plus 1. Plus 1. Plus 1. Plus 1. Plus 1. Plus 1. So, remember to take over the duck. Just take over the duck. Honestly, the duck is perfect. So, It's one, two three four, five different things. Okay. This is just the example we have done, these are the examples we have done, we have a set of rules to find out the oxidation number that also we will see but before that one last case we will discuss here, the third case we will write down, in case of coordinate bond, in case of coordinate bond, discuss the first you write down, first case you write down, when it is directed from less electronegative element to more electronegative element. This is not that much important just to write it down, less electronegative to more electronegative. In this we write down, in this case 2 charge is given to more electronegative atom, plus 2 charge is given to less electronegative and this information I am giving you, right this should, you should keep in mind. Now the structure of anything minus like this, since we have got the oxygen bond should be signal to the electronic sector, this is the structure, coordinate bond we will discuss first we will write down this, now because of this you see this double bond so we will have plus 2 charge given, plus 1 and what is the rule for this, oxygen is more, first the most electronegative element, very important, electronic in periodic table, then we have also, right, so you see now, what is the total charge here, plus 5, so oxidation number of nitrogen here is, plus 5, okay. Similarly, if you calculate by x method also, if nitrogen, because the charge is minus, yes, x equals to what, plus 5, okay, now you see our oxygen has 2 lone particles, not air effect, not efficient, yes or no, it is the bond which forms between the 2 and the same amount, right, here you see in case of ACS, 1 and 1, so when the bond generates from the same amount, the bond form is known as coordinate bond, we will discuss this thing in detail in chemical bonding, this arrow is directed towards the electron pair, accept it, donor, right, this is what the charge here, all these things, if you are not getting it right, what you have to keep in mind, then you will give minus 2 to plus 2 charge and the charge should be 2, no, actually you see, actually what happens, this is donated stone pair of electron, but nitrogen is still coordinated, I don't know, 1 electron is completely donated stone pair of electron, right, so the charge should be 2, no, actually you see, actually what happens, this is donated stone pair of electron, but nitrogen is still bonded with, I don't know, 1 electron, it is completely donated to hydrogen, here we have 2 electrons, but this electron is completely with this hydrogen, 1 electron is still associated with this actually, so actually what you see, actually whatever, it donate this electron, but half of the 1 electron is associated with nitrogen and half of it associated with hydrogen, similarly for other electrons also, that's why it means you have 2 electrons associated with the same energy, because they are in that part, right, that's why you give 1 even positive charge, understood? How I suppose you do all this? How I suppose you do all this? I am telling you this, no, this is only I know, this is I know actually, chemistry is very difficult to study or not, thanks, that's why I am telling you, see, again I am telling you, discuss this in detail, how this coordinate what you have to understand, what is the oxidation number, how do you know, that's what my job is, I have to let you know, where what happens, that's what I am suppose to do, few things you can study from the book, but not everything, okay, and in one book other things are not given, right, so one more case in this to write down the second case, write down, when it is directed from less electron, there is no contribution of coordinate 1, where it is directed from more to less electron, for example, you have feasible point 4, 1 1 to this column, this is the coordinate quantity, right, so the contribution of this point is 0, we have minus, that is it, okay, this is the structure of how we want to see, okay, draw the structure, and direct it from more to less, more to less, okay, understood, and one more thing this, I know you have some confusion in this particular coordinate point, right, this is not very common, you will not get this, usually, but since it is there, it is there in this limit, you should know this, so if you are not getting this, we will not be, once we are discussed, we will do this again, right, so don't worry. Now, these are the few things we have to keep in mind, but like I said, first question number, rules for oxygen, no, for few elements it is fixed, the oxygen number is fixed, I will tell you, first point to write down, direct from more to less electron, there is no contribution, first point, what is the element, what are you doing? group 1, what? I just, you know, first point to write down, what is the element? In case of an element, the oxidation number, in case of what? L element, L element, group 1, the oxidation number is all, even other way, it depends, it is not always, okay, that is why we have, that is true, always, that is true, in case of an element, the oxidation number, the oxidation number of chlorine is always minus 1, oxidation number of L element, fourth point, the oxidation number is always 0, free state and the minus state is always 0, right, so I will write free state and the minus state, oxidation number will be 0, next point, the oxidation number of oxygen is mostly minus 2, minus 2 except the first one, in case of L, we put here minus 1, not minus 2, right, next what we have, N A, it is the peroxide, N A, like O will come there, like, where is the oxygen is to go, so basically, how is N A to go peroxide, like N A, then oxidation is number, oxygen is monomeric, exactly, oxygen is monomeric, oxygen is monomeric, oxygen is monomeric, oxygen is monomeric, but then oxidation number here will be minus 2, I think it should be N A to go, for N A, minus 1 into minus 2, plus 1, N A to go, N 2 to go, examples are this, peroxide superoxide, it is minus 1, yeah, in case of superoxide, superoxide O2 minus, superoxide is, H2 O2, superoxide is 1, K O2, next one we have, what, K O3, example, last one we have, in the first day for other properties, that is why this is one of the method we use for nomenclature of the molecule also, okay, next, next, write out next one, the oxidation number of hydroxyl, the oxidation number of hydroxyl, except in, where metal will take plus, oxidation number of hydroxyl is mostly plus 1, except in the case of metal hydrides, what are metal hydrides, N A H, metal hydrides group 1 and group 2 elements, metal hydride, H2O2 in the last is minus 2, in sulphides, H2S is equals to the charge on the compound, is equals to the charge on the compound or ion. Sir, then N A plus, oxidation number is 1, right? So these are the rules we have to keep in mind, okay, these rules 6, 7, 4, you must remember, next class, we will do some examples on this. Okay. How many of you have done? Ah, same. Ah. What assignment? It's not, it's not. You are not there. Yes? Yeah. No. Okay, sorry. Anyone? Huh? What's your name? Mama. Mama. Mama? No. Pardon? Sir, we could sit here. They have the mass of the soil, mass of the soil is 16, so this minus 40 is the amount of ice. He doesn't have darenite.