 Hello guys, Grapanon. Guys, please type in your name, please type your name in the comment box, all of you who are there, please type in your name guys in the comment box. Hello, Akshita. Only you have joined so far, where are the others? Any idea they are joining or not? Akshita, tell me, should we start the class now? I can see only one or two are there. Akshita is there, I don't see any other people. Guys, type in your name in the comment box, who are all there? Guys, I can't see any one of you. Who are all there, please type in your name so that we can start. Okay, so Venkat, who is this Bharati Ramanan? What's your name? Okay guys, what we did last class, can you tell me? Where were we in the last class? Pre-order properties, have we finished that? Did we finish pre-order properties? Or what was the last portion that we discussed? Can you tell me the last topic that we discussed into that? What was the last concept we were discussing? Trend of ionization enthalpy we did, factors affecting IE we have discussed. Okay, so next you write down the trend of ionization energy. Trend of ionization energy, the first point, as we go left to right, as we go left to right, Z effective increases as we go left to right, Z effective increases and hence, IE increases. The first point is, if we go left to right, Z effective increases and hence, IE also increases. This is the first point. Second point is like in this one, you have what you have to keep in mind that left to right ionization energy increases and the noble gas in each period, actually in each period, noble gas has maximum ionization energy. Noble gas has maximum ionization energy. Alkeli metal has lowest ionization energy. Second point is, as we go down the group, as we go down the group, down the group, ionization energy decreases as size increases. This is the thing we have. Can you tell me this one? Order of ionization energy of group elements of group 2 and elements of group 13. What is the order? Which one has the more ionization energy? Which one has the more ionization energy? Can you tell me? Group 13 has more ionization energy. See the elements of group 2, if you see the electronic configuration, the outermost electronic configuration is NS2 and for this, it is NS2 and P1. So to remove one electron here, it is easier than to remove electron here. That's why the order of the elements of group 2 is more than to that of group 13. So if I compare the ionization energy of IE, ionization energy of magnesium, it is greater than to that of aluminum. Another thing, ionization energy of aluminum is almost equals to the ionization energy of gallium. All these facts you have to keep in mind. The ionization energy of thalium, of thalium is more than to the ionization energy of indium. And the last thing is the ionization energy of lead, lead PB is greater than ionization energy of pin SN. Okay? These points you have to keep in mind. Done. Did you write it? Let me know if you have written it. Now you see some more facts that you should know. The ionization energy of cesium, CS or cesium is minimum in pre-order table. Cesium is minimum. And like I said, in each period, noble gas has maximum ionization energy. For period 2, the order of ionization energy for the elements of period 2 is lithium will have minimum, then boron, then beryllium. The region of this is nothing but this one I have discussed. Then carbon, oxygen, then we have nitrogen, chlorine and in the last we have neon. Nitrogen has more than to that of oxygen because it has half filled configuration, more stable. Can I go to the next page? Let me know if you have written it. Can I go to the next page tell me? Okay. For d-blocks, write down, for d-block elements, for group 3, for the elements of group 3, the order of ionization energy follows this. 5d minimum and then 4d and then 3d. Example we have already. And the example is we know a scandium is maximum, right? So I will write down 5d elements is lanthanum and this is yttrium and this is scandium. This is the order we will follow for the elements of group 3. For group 4, 5, 6 and 10, for group 4, 5, 6 and 10, the order is 3d minimum, then 4d and then 5d. This is what you have to keep in mind. For group 7, 8, 9, 11 and 12, the order is 4d minimum, then 3d and then 5d. This is what you have to keep in mind. Okay. One more important comparison we have for boron family and carbon family. Boron family and one more we have that is carbon family. For boron family, the order is maximum for boron, then thalium, then gallium and then aluminium and then indium. The trend is very irregular. That's why these are important you must keep in mind. So basically here what you have to keep in mind for boron family 1, 5, 3, 2, 4. One is the first element, fifth element, third, second and fourth element. So 1, 5, 3, 2, 4 you have to memorize for boron family. For carbon family the order is this maximum for carbon and then silicon, germanium, lead and tin. So we have only difference over here because of lanthanide contraction. The reason is lanthanide contraction. One important thing we have here like if you have to compare the ionization energy of the element like n, n plus and n minus 3. Okay. Can you tell me what is the order of ionization energy? Suppose if I write down this is first, second and third. What is the order we have of 1, 2, 3? Can you tell me the order? 3, 1, 2. 3 will be it is increasing or decreasing order. Negative is the least and why is that so? See if you see the electronic configuration of nitrogen, the outermost configuration is what? 2S2, 2P3, half filled configuration. For this it will be 2S2, 2P2 and for this it will be 2S2, 2P6. Because we are adding 3 electron here. So if you see the electronic configuration, this has completely filled. This has 2 electron in the outermost shell, P shell. It is half filled. But we won't consider the electronic configuration in this case. Electronic configuration we won't consider. So what you have to keep in mind here, for same element, see there are 2 factors. One is size that you are telling Advaita and other one is electronic configuration. So for same element like N, N plus N minus 3, we won't consider electronic configuration. So electronic configuration is not considered. And we will consider only charge. We will consider charge factor. So you see here N minus 3 has maximum size. So size of N minus 3 is maximum. Then we have N and then we have N plus. So this is the order of size. Size for N minus 3 will be maximum. Size increases. And when size increases, ionization energy decreases. So order of ionization energy will be this, increases. So it is maximum for N plus, minimum for N minus 3. So must keep this in mind. When you have same element N, N plus, N minus 3, then we won't consider electronic configuration, but we will consider size. When you move on, done. Are you there guys? Next you write down electron gain in helping. Delta EG H negative. This is electron gain in helping. Write down, it is the energy change occurs. I'll write down the definition. It is the energy change occurs for the process of adding an electron to an isolated gaseous atom to convert it into a negative ion or negative ions. So the thing is when a gaseous atom we have, and when you add an electron into it, it converts into a negative ion that is AG minus. And in this process, the energy that is involved, that energy is the electron gain in helping. In this process, what happens? Energy, energy generally, energy generally increases, generally releases. Energy generally releases, but it may, it is possible, but it may get consumed. Generally energy releases, but it may get consumed depending upon the atom that we have. Next you write down the electron gain in helping. Delta EG H negative is generally negative. The value is negative. And this negative means, this negative means that the energy releases. It is the convention actually. Energy releases. Negative means energy releases into this. So if energy gets consumed, then the value will be positive. So minus and plus only includes that whether the energy only reflects, whether the energy is getting released or getting consumed. That's the only thing. One point you write down here, this one is important. More negative electron gain in helping, more negative electron gain in helping, more will be the tendency to accept electron. More negative, more will be the tendency to accept electron. One more thing, one more term you write down here, that is electron affinity. Both will discuss together. Electron affinity. It is the tendency for an atom to accept electron. It is the tendency for an atom to accept electrons. Electron affinity it is defined as, defined at absolute, absolute zero temperature. The energy relation of the electron gain in helping, delta EG negative with electron affinity, that is minus of AE, this is electron affinity. AE is the electron affinity, minus of AE, minus 5 by 2 RT. This is the relation of electron gain in helping and electron affinity. Did you write this? Can I move on to the next page? Yes, R is the universal gas constant. T is the temperature of Venkat. Guys, there is a problem. I have to go out. There is an unavoidable circumstances with me. Just now you got a call. So I am not able to continue this class now. But we will have this class some other day. That detail I will let you know. Venkat and Advaita. Sorry, I have to leave. T is the temperature, Venkat. T is the temperature. Absolute, one last thing, absolute zero temperature is zero Kelvin actually. That is minus 273 degrees Celsius. This is absolute zero temperature. But Advaita and Venkat, I am not able to continue this class now. I have just got a call. You have to rush to Inran Nagar right now. There is an emergency. Take this class some other day. I am sorry for this. Bye bye, take care. Thank you.