 can classify it into two different categories, first one is plus i and second one is minus i. The groups which shows plus i nature and the groups which shows minus i nature, okay. Depending on that we will have the stability and aesthetic and basic nature we will discuss. So what all groups which shows minus i nature and which shows plus i nature. Generally the number of groups which shows plus i nature are very less in comparison to minus i, right. So minus i group like here in this case you see this chlorine atom shows minus i effect and why so because the electronegativity of chlorine is more than that of carbon, okay. So whenever the electronegativity is more it always shows minus i effect, okay. So that is what we are going to discuss. So first thing we are discussing here is minus i group. For example you see all hydrogen atoms shows minus i nature, chlorine, chlorine, bromine and iodine. So the order of minus i effect is this decreasing order and why so because electronegativity also decreases, okay. Now the next example we take if you compare the minus i nature of OH SH. I will just write down few examples here and then we will compare, okay. OH SH will write NH2, PH2 will compare, okay. We can do all these questions. You can pause the video and you can do this. I am discussing this here, okay. Like you see all hydrogen atom shows minus i group, decreasing order is this. OH SH if you compare, okay. So OH SH if you compare so obviously we can see the oxygen is more electronegative than sulfur and sulfur. So order of minus i effect will be this. NH2 and PH2. Nitrogen is more electronegativity. Having more electronegativity order will be this. NH3 plus and NH2. Nitrogen having positive charge has more tendency to withdraw electron order will be this. Oxygen having positive charge have more tendency to withdraw electron order will be this. Nitrogen attached with two electronegative atom here that is oxygen and here it is only one so it has more electron withdrawing tendency. If you compare fluorine, oxygen and nitrogen, fluorine is more electronegative than oxygen and then nitrogen order will be this, okay. You see in this group if you see this example, this one right. In these two examples you see we have a difference in size also oxygen and sulfur. These two belongs to the same group, right. Oxygen, sulfur and then other elements we have. So when the size difference is there in the same group then as the size increases minus i effect decreases, right. So that's what we can say here in the same group size increases minus i nature decreases, okay. Minus i nature decreases. For the same kind of elements we'll see the electron deficiency of that element. Obviously nitrogen having positive charge on it it is more electron deficient than this. This has more tendency to withdraw electron. Oxygen, oxygen having positive charge more tendency to withdraw electron minus i group will be more. Nitrogen, oxygen this is common in this one and this example but since we have one more oxygen atom this will withdraw electron towards the side making this nitrogen atom comparatively more electron deficient it has more tendency to withdraw electron. In this example you see there is no such large difference in size, right. Both are all fluorine, oxygen and nitrogen belongs to the same period, right. The second period. So there will be size difference but it is not that much, okay. So in this kind of examples we'll discuss minus i effect will you know explain on the basis of the electronegativity difference. So more electronegativity more will be the minus i nature. So fluorine, oxygen and nitrogen order will be this, okay. Few more examples I'll write down you see. Fluorine S H C N C H double bond C H 2 C triple bond sorry C H 2 C F C C double bond O C L and C double bond O H S double bond O double bond O O H S double bond O H C F 3 C C L 3 C V R 3 and C I 3 N H 3 plus N N R 3 plus, okay. Now I am discussing all these examples the minus i order of all this group. You can pause the video and do it on your own and then you can compare, okay. Now again you see fluorine and S H. So first example, fluorine and S H. So these two elements belongs to the third period and when they belongs to the same period we'll see the electronegativity not the size. So electronegativity of fluorine is more it has more minus i nature, okay. Now here you see this carbon atom having S P hybridized this is S P 2 this is S P 3, okay. Two things we can discuss here obviously nitrogen being more electronegative so it will draw more electron towards its side making this carbon to withdraw more electron from the group, right. So obviously because this nitrogen atom this carbon becomes most electron become more electron deficient in this or this carbon atom and hence the electronegativity order will be this, this and this. One thing you can show from this electronegativity of nitrogen that the first molecule which is nothing but this having the most minus i effect, right. But we cannot compare these two then, okay. So how do we compare that? We compare this on the basis of percentage S character and with percentage S character we can easily explain this order, okay. This carbon has S P 50 percent percent is S character this has S P 2 33.3 percent S character this has S P 3 25 percent S character and we know as S character increases I'll write down here as percentage S character increases electronegativity increases, right. So this is a most electronegative than this and then this order of minus i will be this. Now this example you see chlorine being more electronegative than hydrogen it has more tendency to withdraw making this carbon more electron deficient and hence the minus i of this is more than to that of COH, okay. Now in this molecule we have one more double bond O group so this will withdraw more electron than this order will be this. CF3, CCl3, CBR3 and CI3 the order of minus i will be for fluorine is maximum then bromine and then in the last the chlorine then bromine and then in the last is iodine. SH3 and NR3 plus, right. You see this molecule SH3 and NR3 plus I'll write down here again, okay. Now these are the alkali group we'll have a little bit of idea and these alkali groups has tendency to release electron, electron releasing tendency and this tendency of these alkali group is obviously more than to that of hydrogen, right. So when you compare this nitrogen this nitrogen the electron deficiency of this nitrogen is obviously more than to that of this nitrogen, right because of the electron releasing group of electron releasing group, electron releasing nature of our group, right. So if you see the electron deficiency of this one is more so obviously this has more tendency to withdraw electron so order of minus i should be more for NH3 plus than that of NR3. This you can do with the logic that we are discussing till now but actually the order is not this, this is not the correct order here, right. This is one kind of exception you can understand or we can also explain this in a different way. First of all let me give you the correct answer for this order and the correct answer will be it has NR3 will have more minus i group than NH3 plus. This is the right answer of the right order. So first of all you have to memorize this. Now how do you explain this first of all you see this nitrogen and this alkyl group if the bond forms between these two here so this has p-character and this has p-character because p-p orbital will get overlap, right. Similarly here also p-n-p overlap p-n-p overlap so what we can say since the p orbital is in is involved in bonding then this nitrogen will have more s-character, right, more s-character. Now the s orbital of hydrogen involves over here in bonding so this nitrogen has comparatively less s-character here, right. Now since this nitrogen atom has more percentage s-character so it has more tendency to withdraw electron and hence the order of minus i is this, right. So this is one example that you will must remember it is very important example we have order of minus i of n is 3 plus and NR3 plus. Similarly on this way we can also give you one more you know minus i order which is OH and OR. So here also we have the same kind of order OH will have lesser minus i than OR the logic here also it is same as this, okay. So these two examples you must remember it is very very important, okay. The minus i effect of n is 3 plus NR3 plus and OH and OR understood. These are the few examples you can also memorize these that which all group shows minus i effect and which all group shows plus i effect okay but with you know with common sense also you can compare and understand that the group will withdraw electron or release electron, okay. You must have seen the order given in the books minus i order and plus i order but I will suggest you to use some common sense and then you can compare the minus i order of various groups like we have compared right now. Few examples I have shown you already the way we have compared like that you can compare easily the minus i nature of that okay and I am also giving you here the order of those groups okay minus i order of those groups if you want you can write it down I will just write it on the board okay. So the heading is guys so this is the order of minus i group maximum we have for NF3 plus maximum minus i minimum we have for hydrogen okay few things you can compare here also okay let me tell you first of all all these all of you know this chlorine chlorine bromine iodine you don't have to put any effort to memorize this now if you compare if you have to memorize this we have carboxylic group and this is the ester right so in between carboxylic and ester we have halogen this is the point you have to take care of okay and if you have to compare this like if you know this suppose we have carboxylic and ester and in between we have halogen group and if you compare this carboxylic group and the ester group which one will show more or minus i that also you can compare easily I'll write down here you see C double bond O OH and C double bond O OR so till here you see till here it is same C double bond O O C double bond O O the difference of what we have hydrogen here and alkyl group hydrogen and alkyl group so which one will show more minus i which has more electron with drawing tendency right and this electron with drawing tendency of this group will be lesser than this first one because this alkyl group has electron releasing tendency but this kind of electron releasing tendency is not here so because of this electron releasing tendency this group will show lesser minus i then C OH group correct now in between these two we have halogens so this is floating grooming point okay now similarly you can compare this C double bond O OR I'll write down here C double bond O OR with OR so this group is same here and here also we have an extra C double bond O group which has electron with drawing nature right C double bond O will also withdraw electron so easily you can say the minus i nature of this is more than the OR group OH OR we already discussed NF3 is maximum NR3 NS3 we also have discussed these three you have and all other things are easily you know you can easily keep in mind the order of all other groups here these are the few examples of minus i group we have discussed so far that how do we compare the minus i nature of various group right and we have also given the order of minus i group which you know few things you can memorize feeling when keep in mind logically also that helps you in solving the questions in deciding the you know acidic basic nature and stability of various okay so this is it for minus i group we'll discuss next what is plus i nature on releasing effect the group which shows CH2 methylene electron with drawing nature drawing nature electron with drawing nature and then we have C double bond O all these has electron releasing nature okay there are very few examples of electron releasing group most of the groups are electron withdrawing only okay one more order we can see this is the first one we have discussed another one you see if you have methyl group if you compare the signature of this and this group instead of one hydrogen here one hydrogen here we have one methyl group and this methyl group has electron releasing nature right this has two methyl group so we have two electron releasing group present here this has again three methyl group three electron releasing group present okay so the electron releasing tendency of three degree carbon here this is two dc carbon and this is one degree carbon and this one is methyl so electron releasing tendency of three dc carbon is maximum then we have two degree and then we have one degree and then we have methyl okay this is the electron releasing nature one more thing here we have to keep in mind that the isotopes of hydrogen okay like tritium deuterium and hydrogen that is the order will be this for electron releasing nature it is maximum for ct3 then cd3 and then cf3 protein okay this is the order of when we have isotopes of hydro this is very important example we have you have to keep in mind tdH decreasing order right mdH tdH you can memorize like this ct3 maximum then cd3 and then cf3 okay bond length you see the high we have some logic also you can put here some vibration thing but that is not required you just you can memorize this and you will understand okay the bond length order of this bond is reverse okay if I write down the bond length order of this group it is you know maximum for ch then we have cd and the last we have cd bond length order okay these are few groups which shows plus i nature okay and like you see there are only few groups which can show plus i nature all these are not at all important also right this is somewhere it requires the application of this this is also required okay so there are very few groups which shows plus i nature electron releasing nature and we have also discussed the example for that okay so next session we'll see the application of plus i n minus i effect okay how it affects the stability and acidic and basing nature of the compound thank you