 discussing here is. So, stability of alkene it depends on the number of hyper conjugative structure more hyper conjugative structure more will be the stability. What we can say stability is directly proportional to the number of alpha hydrogen stability is directly proportional to the number of alpha hydrogen. Now, this is stability that is stability due to due to stability due to hyper conjugation. If you compare stability due to hyper conjugation just we calculate the number of alpha hydrogen, but for in a given molecule you can have all kind of effect possible. We can have resonance also in a given molecule resonance is also possible we can have hyper conjugation is also possible and we can have I effect also possible. So, when all these effects are there in the molecule or when there are more than one type of effect present in a molecule then the stability will define or will find out in this order. Resonance is the dominating effect here. So, in the given molecule if resonance hyper conjugation both are possible then resonance effect will be dominating or if two molecule if you have to compare one is showing hyper conjugation and other one is showing resonance then the stability due to resonance will be more that is because of hyper conjugation and then we have I effect. I effect the least effect we have and all these effects are dominated by aromatic aromaticity. So, aromatic effects is the most powerful effect and that will dominate all other effect resonance hyper conjugation or inductive effect. So, this you must keep in mind stability of alkene if and only if hyper conjugation is possible then we just calculate the number of alpha hydrogen, but in case of resonance will have resonance is dominating effect I effect if it is there then hyper conjugation will be the dominating effect. We will see few examples on this and then you will understand how to compare the stability of alkene when various electronic effects are there in a molecule. So, we will see some examples now. So, all these questions are we have to find out the stability order. Now, you see all this example first question the number of alpha hydrogen here is 12 number of alpha hydrogen is 9 alpha hydrogen 6 number of alpha hydrogen 3 number of alpha hydrogen 0. So, order of stability will be what most only hyper conjugation possible alpha hydrogen maximum then this this this is the order first again third fourth and fifth decreasing order it is. Now, this is the alpha position alpha position alpha position and alpha position alpha hydrogen will be 8 and the alpha position here is this one and this one. So, alpha hydrogen here it is 3 mode alpha hydrogen mode will be the stability. I forgot to tell you here that hyper conjugation is possible in alkene as well as alkyne also. So, there in the initial where I have written it alkene carbocation and free radical they write down alkene or alkyne in both hyper conjugation is possible. So, number of alpha hydrogen here it is what 3 number of alpha hydrogen here it is 2 mode alpha hydrogen mode hyper conjugative structure mode will be the stability. Number of alpha hydrogen 3 right 3 2 5 and 2 7 number of alpha hydrogen 1 stability order will be this number of alpha hydrogen 3 and 3 6 number of alpha hydrogen 2 stability order is this ok. So, like this we can compare the stability of alkene when only alpha hydrogen is sorry when only hyper conjugation is possible ok few more example you see OCS 3 you see this one is aromatic compound and this one is anti aromatic right stability order is this ok. This one is oxygen has lone pair. So, here we have resonance possible right and here we have hyper conjugation 3 alpha hydrogen number of alpha hydrogen here it is what 3. So, resonance is more dominating stability order is this ok. So, like this we can compare the stability ok. So, whenever we have alkene and only hyper conjugation is possible just you calculate number of alpha hydrogen mode alpha hydrogen mode will be the stability, but when we have resonance and hyper conjugation both are possible then the resonance will be the dominating effect ok according to that will define the stability. There are few examples in which the number of alpha hydrogen is same ok. So, in that case what we will do ok how do we assign the stability that we are going to discuss now alpha hydrogen. For example, if I draw this ok. So, you see here the number of alpha hydrogen is 6 number of alpha hydrogen is 6 number of alpha hydrogen is 6 ok. So, in this case what happens whenever the number of alpha hydrogen are same and only hyper conjugation is possible then what we do will draw the hyper conjugative structure ok. So, for this one if I write down the hyper conjugative structure ok. So, what happens this sigma bond comes over here pi bond will come here right and the hyper conjugative structure will be this C H 2 C single bond C H 2 negative C H 3 here we have H plus and double bond will have here ok. Now in this if I draw the hyper conjugative structure that will be C H 2 H C double bond C C H 3. So, hyper conjugative structure it will be C H 2 H plus double bond C H double bond C H sorry C H 3 here we have the negative sign ok. And in this case if you draw the structure C H 2 H this sigma comes into pi and the structure here it will be C H 2 H plus double bond C H C H C H 3 ok. So, now the point is what is the difference in all these structure right what is the difference in all this structure. First of all this carbon ion is 1 degree we are getting carbon ion 1 degree this is 2 degree and this is 2 degree ok. Suppose this molecule is A this is B and this is C ok. So, molecule A gives 1 degree carbon ion if you try to draw all the hyper conjugative structure you will always get 1 degree carbon ion, but B and C gives you 2 degree carbon ion always. So, obviously since 1 degree carbon ion is more stable right. So, obviously molecule A is most stable over here right and in the second case what happens since both we have 2 degree carbon ion and this one is trans right. So, 2 C S 3 group is far away from each other in comparison to this one ok. So, hence this one is more stable less will be the hindrance B is more stable than C. So, order of stability will be A B and C right because in this B second molecule both methyl group are at the maximum distance less will be the repulsion and hence the order will be this. So, if you have equal number of alpha hydrogen present draw the hyper conjugative structure compare the carbon ion if it is 1 degree 2 degree 3 degree we know the order of carbon order of stability of carbon ion 1 degree is most stable then 2 and then 3 right. So, accordingly we can write down the order of stability. If you have both 2 degree then we can say that these 2 C S 3 group is a transposition far away from each other and hence less hindrance more will be the stability order will be A B and C you can go through this.