difficult item. Okay. Something which is very new to all of you. So I hope that during the weekend you took the time to try to understanding. Okay. In fact right after convention the other day uh I have quite a number of students who came to me and ask me also. All right. So good that if you don't understand please come and ask me directly. Okay. trying to clarify but that's okay I think this mic is better okay if you don't understand quickly come and ask quickly come and clarify because we still have a lot a lot a lot more meaning things for you to understand okay if you keep on delaying then there are more things that you don't understand it will end up that you don't know what you are trying to learn from here. Okay. All right. So let's look at what we have learned. Okay. In the previous lecture. So first okay we wrap up on mass spectrometer. Okay. From the mass spectrometer we produce a graph and the graph is called a mass spectrum. Okay. So can you briefly tell me there are a few informations that you can get from a mass spectrum. Okay, this is the percentage abundance and then this will be the mass over charge ratio. Right? There are few information that you can get from a mass spectrum. Can you tell me uh what are the information you can get from a mass spectral? Number of Okay. Number of isotopes. Number of isotopes is based on what? How you know how many isotopes are there? Okay, how many lines? Okay, or we actually call them peaks. How many lines? Okay, so this is one line. This is two lines. Number of isotops. Okay, what else? The mass of the isotop. So from the mass of the isotop, what can you know next? identity. All right? For example, you have sodium. So let's say this mass is 23. This mass is 24. So you know that the identity from this mass of the isotope. You will know the identity. This is sodium 23 and this is sodium 24. The identity. Okay. And the last one you will know the abundance. All right. Percentage abundance. Please take note for abundance. All right. So sometimes they put as percentage abundance. So if it is percentage of course you will know it will toggle up to 100. But sometimes they use the word relative abundance. All right. So if they use the word relative abundance it will not be 100. Okay. It can be 9, it can be 16, it can be number. It just means the total abundance. Okay, that's why always try to total out the abundance. Not necessarily it will be 100%. Okay, so this is uh we how we wrap up on the mass spectrum. Uh also learn to calculate how to read the mass spectrum and calculate relative atomic mass. Okay. Okay. So let's look at the new thing that we learned. Okay. So before this you learn about main shell. All right. The one that's closest to the nucleus is the first shell. The next second shell and the furthest away from the nucleus is the third shell. N= to three. Okay. But now we learned that the shells can then further be divided into what we call shells. All right. Stock means inside the shelves. Okay. So subshells. So subshells depend on those shelves. Okay. N= 1 2 3. For example, we mentioned the other day if you have n = to one. The first shell. How many subshell do you have? One. N= to three. Three. Okay. Okay. And the first top shell is always as followed by P and the next D. Okay. So all this I think you have understood. The only thing that I want you to take note is this. Okay. So I have mentioned also we go according to energy level. Everything is arranged according to energy level. So 3 S 3 P after 3 P what is the next energy level? 4S. It means that no matter what when you fill in in uh electrons after 3 P fill in 4s first only when 4s is fully filled then only you go to 3D you fill in 3D. Okay. Okay. And after sub shell we then have what we call orital. Okay. Orbitals. What do you remember about orbitals? What are orital? They are bosses. What else? Okay. One box can fit two electrons. What else? The term orital. What is orbital? No, it's not. No, that that is orbit. But this one is oriental. It is something else. What is orbital? Region. All right. Region or space or area? Space for what? Okay. But there is a more than 90 or 95% chance of you Finding electron that is the real definition of orital. All right. Orbital actually show you the region, the space or the area where you have more than 90% chance of finding the lateral. Okay. Okay. And then this region, this space, this area depends on the shape. So each orbital has their own shape. I have S, I have P, I have D. They have their own shape. And the shape represent represent the space, the area of me finding electron. So what is the shape for S orbital? Spherical. Okay. Spherical basically means round. Pell. All right. dumbbell shape and the double dumbbell. Like I say, you don't need d sorry double bell. Okay, like I say, you don't need to draw. You only need to know what is the shape. What is the correct shape? Okay, and this shape represents the area that you can find electron. Okay. And of course each orbital show different number of electrons that you can fill in. For example, S orbital can fill in maximum how many electrons? Two P six and D 10. Okay. So it means that within the double dumbbell shape you can find a total of 10 electrons. Within the dumbbell shape you can find a total of six electrons. Within the spherical shape you can find a total of two electrons. Right? Okay. So let's go back to our learning outcome track. Okay. Uh we learned about main shell. Quantum shell means the main shell. Okay. Represented by n = to 1, n= to 2, so on. We learned about subshell. All right. We learned about orbital, the region or space. Okay. And all of them they are arranged according to energy levels. Okay. So I have put an arrows. For example, n = to three. As long as the further away they are from the nuclear, the higher their energy level. Okay. So likewise for stuck shell. Okay. So 1 s 2s until 4s lower energy level 3d higher energy level also arrange according to energy level. Okay. So when you fill in electrons you fill in from the lowest energy level. Okay. And then next we learn about orbital. What is orbital? We have already answered region or space where you have a higher chance of finding electrons. And then the shape of orital also we have handle. And lastly the rules to arrange electrons. Okay. We have three rules to arrange electrons. Okay. We have number one asbal. So as principle says that we arrange the electrons according to energy level from the lowest to the highest energy level. All right. What does it mean from the lowest to higher? 1 s 2 s and then after 3 I must fill in 4s then I fill in 3d. Second I have polyexclusion principle. So polyexclusion X means must be in opposite spin or opposite direction because one orital one box I can fit in two electrons. So both the electrons must be in opposite direction. And lastly I have HS rule. All right. H rule says that I must fill in electrons individually before I pair them up. For example, if I have 2 p3, then I must fill in individually first. One electron, two electron, three electrons. Okay. All right. So, these are the things that we have learned. We have a take all of this. Do you have any questions? Anything you want to clarify? No. Okay. Let's do a bit of uh exercise. Okay. So, calcium I have 20 electrons. Can you arrange this 20 electrons for me? 1 s2 2 s2 to be 62 6 for s2. Anything else? No. Okay. So here you can see that the electron configuration n = to 1 I have two electrons. n = to 2 8 n = 3 8 n = to 4 2 Okay, next we try 21 electrons. 1 S2 2 S2 2 B6 3 S2 3 P6 4 S2 See how I put them apart. I fill in for S2 first and then what is next? Where should I put 3D1? After 3P 3D1 okay so this is one thing that you have to know. So once you fill in 3 P you fill in 4 S first but you leave a gap and if let's say you have to fill in 3D just write them here back here. Teacher why do I have to write them together? Because I want to group all the n= to 1, n = 2, n = 3 and n = to 4 together according to their shells. All right. So first shell how many electrons? Oh sorry two. 7 8 third 9 and fourth two. I group them together. Okay. Maybe we try one more. Iron iron 26. Okay. 1 s2 2 s2 2 p6. Okay. Okay. You see 4s2 put very far first and then 3D 2 10 20 26 6 2 D6 sorry 3d6 okay so 26 electrons here I have 10 here I have 20 so 26 you have to calculate okay so let's Three. Okay. First down. Two. Second. Okay. Third 14. Okay. So, how many maximum in the third shell? 18 maximum can reach up to 18. Okay. All right. So, very good. Seems like uh you guys understand what you are doing. How to arrange them and how to write them. Especially if you have 4s and 3D. Okay. All right. So, if you have do you have any question before we continue? Okay. Okay. The quotes for today. Okay. Welcome to week five. How many days do you have in foundation? 12. What? Okay. So, it's already week five. We are almost halfway. Okay. So, ask yourself how much have you learned for everything so far. Okay. You don't need to be the best because the best normally can only have one person who got the champion. Okay. The best there's only one person. But what you need to do is you try your best. Okay? Be better than who you are last week. If for example last week you still don't know one next two B3 you still don't know how to arrange but this week you already know how to arrange that is very good all right you improve every week ask yourself how much have you learned if right until now you learn nothing maybe it means that this part is not suitable for you maybe you want to reconsider another journey okay another place where you like to study pattern. Okay. Okay. So today we are also going to after this we are all dealing with a lot of new things. Okay. Chapter one a lot of revision. So now chapter 2 three. Okay. What is some new things? Okay. So when we talk about this I also wish to do a bit of revision with you. This is the periodic table. In periodic table they are divided into groups. Group one, group two, three until 12. What do you call this? Transition. All right. So, transition elements means the special elements with special properties. So those that are nontransition all of these 1 to 13 until 18 we call them main group elements. Okay. So when we learn about properties we usually talk about main group and for transition we will learn separately in chapter 3. Okay. All right. So in the periodic table group how do you know their groups? groups are according to what? What are valence electrons? Okay. Electrons in outer most outermost shell. Okay. I I can tell you that more than 50% of my students after learning 1 s2 22 32 they will go and say that balance electrons for example I have this one 3 s2 3 p 23 what is the valence electrons how many valence electrons are here how Five. Why is it five? Main last outer most shell. So my outermost shell is n = to three. Third shell. So how many electrons are there in third shell? Five. But after learning this some students got confused. They thought that there are three valence electron. No one. So valence electron according to shell. Look at the main shell. Okay. So don't get confused. Remember this. Okay. Of the group we have next what? Period. Period in the periodic table. Period 1, period 2, period 3, period 4. So what are periods? According to number of shells. Okay. So period two means I have two shells. For example, 2.1 barium 2.2 two two shells. Okay. And now we are going to learn something new. I call it block. Okay. So, periodic table can also be divided into blocks. So, what are blocks? Okay. blocks are according to highest energy orital filled with electrons. Let's say just now 3 s2 3p3 which is the highest energy orbital p highest energy orbital is p. So which block is this? P block. So remember this is group 15. So group 15 is under p block. Okay, let's take another example. 2 S2 2 P5. Which group is this group? Which group? 17. Okay. So, group 17, which block P block. So, 17 P block. Okay. So, it's according to highest energy orital. Okay, let's take one more example. Okay, in which block? Okay, highest energy orital electron. Okay, how many of you say X block? I'm going to say D block. Okay, it's D. Okay, so this one after I fill in 4s, I touch 3d. So the highest energy that I with electron is actually 3d because I have reach until 3d level. All right. So only this until here it's d block. Okay. When you have D and S is usually D block. If you have only x for example 1 s2 2 s2 26 3 s1 it stops here until s then this is s block but if you have d and s then it is d block okay can give you some time to digest this a new term block is according to highest energy orital so ask yourself when you fill it according to above Which is the highest energy you touch? That is your block. Okay. And continue. Okay. Now again I want to try to write down the electron configuration for chromium 24 electrons and next I have a copper 29 electrons 852 remember. Okay chromium 24 electrons copper 29 electrons. Can we try to arrange these electrons? Okay, try to arrange for me. 24 electrons. 1 S2 S2 2 S2 P6 S2. Okay. So 10 20 24. Okay. So this is the electron arrangement according to our according to building up principle. Okay. But I'm going to drop another bone. Remember there's many bones in chemistry. There's a lot of plot tw okay. And my bone sounds like this. Okay. Okay. Half filled or fully filled orital are more stable. Teacher explain half field. What are half fil? Okay. Let's say I have 3 p. How many orbitals are there in 3p? Three. What does half field looks like? Half. Okay. 3 maximum how many electrons? Six. So half fil means what? Three. This is half field. Fully filled six. This is the meaning. Okay. Okay. So let's say I have here 3D five orital right half field 3D half field five one 2 3 4 5 fully filled 10. Okay. So now I drop you a half filled or fully filled orital are more stable. So what happened to chromium is that when I reach accordingly okay the same until here 3D and 4s how can I make them more stable 3D5 for S1 because 3D5 is half filled for S1 also half fil both are half field both are stable. All right. So 4s says our energy level very close to make us more stable. 4s is willing. Okay. Okay. You take the electron we will have this configuration. Okay. So in the end they are going to rearrange themselves. 3 s2 3 p6 3d5 4s1 they are going to rearrange themselves and this is the official electron configuration for chromium all right it means that whenever I ask you to write the electronic configuration for chromium this is the correct answer okay because this is the stable answer. Okay. So this is wrong. Don't give this answer. It is incorrect. All right. So this is the correct answer. Okay. Let's try for copper 29 electrons. How do I arrange them? 1 S2 2 S2 2 P6 3 S2 3 P6 4 S2 3 P9 supposed to be like this but the same the same shell the same uh bone okay the same exception we call this exception exceptions there are some exceptions in chemistry exceptions mean they don't follow the rule All right. So in order to achieve stability they will bend a little bit of the root. Okay. So look at this configuration based on chromium just now. So how do we rearrange this so that they are stable also 310 for x1 because here I have fully filled and here I have half fil are both stable. Yes. Okay. So let me rewrite the full configuration. 1 s2 s2 to p6 3 s2 3 p6 again this is the correct configuration not this okay so in order to achieve stability. So if let's say you want to come to me and you say teacher I don't understand chromium and copper why they must rearrange like this my answer will still be the same because they need to be stable to achieve stability okay so here they fulfill what they need to do okay so they will rearrange themselves okay give you some time to digest this okay because uh whenever we do any electron configuration dup or pair okay and we arrange electron configuration everything is because we want to achieve stability we want them to be stable a stable configuration do you remember last week we learned a curve there was one curve a stable configuration what is another name for stable configuration stable arrangement of electrons. What's the name that we give them? No, last thing. What state? Yes, ground state. Right. So all the arrangements are so that we achieve. So this is the ground state configuration for copper. This is for pro. All right. Any question? Okay. So like I say this is the official it's real configuration. So you see that scandium 21 electrons. uh if uh calcium 20 electrons we arrange until 4s2. So scandium 21 electrons is 3d1 22 3d2 23 3d3 but when we reach chromium 24 electrons in order to achieve stability it's actually 3d5 for s1 and then they go back to normal mang 3d5 for s_ub_2 copper again in order to achieve stability it is not 3d9 for S2. No. Okay. It is actually 3D T for S1 and then back to sync 3D for S2. Okay. Any question then? Okay. Okay. So, let's try to write the electron configuration for ion. I only have one tip, okay, for you. One tip for you. When you write the electron configuration for ion, write the configuration for atom first and then only you remove or add the electron. All right? Always start from atom first. Okay. Let's try example one. I have a sodium 11 electron. Okay. How do I arrange this 11 electrons? S2 2 S2 2 P6 + 1. Okay. So, sodium positive which is the electron removed. Which one is the electron removed? 3s1 we always remove. Okay. From the highest energy electron. So highest energy means furthest away from the nucleus. This is the nuclear furthest away from the nucleus. So I'm going to remove the and it will become 1 s2 2 s2 6. Next I have chlorine 17 electrons. So try to arrange this. 1 S2 2 S2 P6 3 S2 3 5 and then I have a negative means I'm going to add electron where do I add this electron into P also from the outer most okay so it will then become -2 2 2 S2 2 P6 3 S2 3 P6. Okay. Okay. Next, I have a few examples, a few questions, five questions. Can you try these questions while I go around with past the attendance? Press attendance. 6 8 and 7 n where nine the attendance for fis9 I collect all the attendance first where the attendance sheet for fis9 N. Okay. Uh so if I text who hasn't signed eight seven down Where's J? Who else had very good. Some of you are even doing some other question survey. I7. What else is inside? Okay. Uh let me give a bit of pep talk like a grandma first. Okay. So a lot of students before they come to foundation they actually got very good results, excellent results. Okay. But when it come to foundation uh you know right foundation is not according to how many A's you have but foundation is according to uh CGPA okay so maximum is 4.0 CGPA okay so from a background of very excellent school a students come with full scholarship but when they come to foundation suddenly they fail some courses and then they got below 2.0 0 out of 4.0 which means less than half even less than half. All right. So what happened was actually because before they come to foundation they have parents they have grandparents they have people who monitor them. Do this do this you have a 10 people so you go to school correct right all of you before you come to foundation your parents will always force you to study but when you come to foundation you're far from your family. Okay. Then I start to see some students or in the class they are going to play games. Okay. They're going to uh text friends, use the phone. When I say do the exercise, don't do anything. Come to the class without any pen or pencils. Just come empty handle. Just walk in and sit down. Okay. So this is what you have to reflect on your own. Okay. Okay. So they're going to discuss I'm not sure why but big five I still have students sitting behind the pillar. Uh I don't know what's his name. White color shirt. What's your name? What's your name? Huh? Okay. Anyone knows his name? I cannot hear. Can you please don't sit behind the pill because I cannot see you. All right. Okay. Let's discuss this. Okay. So, I think uh this one one no problems four no problem. Okay. So, can we write the electronic configuration for alum medium 13 electrons? Okay. So I will have S2 2 S2 2 P6 3 S2 3 P1. So three positive means remove three electrons. So which are the three electrons removed? S and P. All right. So I'm going to remove this. So this is the final answer. Okay. And then I'll look for two first. Sorry. Four first. Okay. So, oxygen eight electrons 1 s2 2 s2 could be four right? Okay. So, I have 2 minus 2 minus means plus two electrons. So, this will be six 26. Okay. Next, copper positive. I wish to know your answer. What's your answer for copper 2 positive number two? Uh, I only want the last two electron configuration D 3d and 4s 3d 10. Okay. Anything else? Okay. Any other answers? 3D9 for S1. Okay. Any other answers? Okay. 3D10 for S1. Any other answers? Okay. Let's see. All right. So, copper I have 29 electrons. How should I arrange this 29 electrons? 1 S2 2 S2 2 P6 3 S2 3 P6 4S copper 4s 1 3D 10 proper configuration we just learned like five minutes ago. All right. So we start from the normal configuration 3d10 41 copper then only I move on to two positive means remove two electrons. So which are the two electrons removed. I must remove 4s1 first and then 3d 9. So the final answer is actually 3D9 this okay that's why I say you must practice that's why I insist you must write that's why this round I walk around and make sure you write because this kind of things you cannot memorize how much can you memorize okay next let's check copper positive what are your last two configurations 3D and 4S. Okay. Any answers? For S1 and your answers only 3D pan and your answers only 3D. Okay. You don't have 3D pen. Do you have 3D pen? only for S1. Okay. So let B 2 and three are the same. So we start from 29 electrons. Again copper 29 electrons. 2 s2 2 p6 3 s2 3 p6 10 electrons and then 4s1 3d10 copper anything start with the atom first and then I remove how many electrons one which one is to be removed 4s1 remove this so What's the last configuration? 3D10. Hey, may I know your answers again? The last two 3D and 4s 35. Okay. Anything else? Any other answers? No, it's okay. At least now you know you are wrong. You know where it goes wrong. Okay. So, any other answers that iron 3 positive? No. Okay. Then let's check. Uh iron is 26 electrons 1 s2 2 s2 2 p6 3 s2 3 p6 Yeah. 4 x2 10 20 so 26 is 3d6 okay and then so here 3 positive means remove three so I remove first from the outer most 4 s2 and then yes 3d5 Okay, always that is why I say the only hint that I can give you is always start from atom first and then we think of the ion which to remove or which to add. Okay. Okay. It's 9:15. Uh I'll have a 10 minutes break. Then we come back 9:25. Okay. And we will discuss the next question. Please so you can go for your breath. All right. Attendance can pass back to me. Is here. Thank you. is here. You haven't signing home from home. Oh, pumpkin. Pumpkin. and die out. has 3D level that's why we like this 3D We need to be a little we just that Oh no. Uh snacks still available in front. Why is it rearrange? So when you fill it in a contract, you can choose something and then as maybe okay now even though Maybe the heat. Yeah. But rearrange the higher energy as ogation. No rearrange is only for like So then it's easier to see when they which was not during the classroom X3. So then we still Yes, That's because very very care. still available in front of you. Thank you. Yeah, sure. I'm not sure if they suit your taste buds. Yeah, you can try. Yeah, you can. Oh, really? Oh, so fast you tasted this. This is Malaysian snacks. Thank you. Okay. Take one. Okay. Yeah. Kids and also business. Okay, we will start with one minute. I do for myself some exercise too. Mhm. Okay. Yes. If two positive then you remove this and yes 25 so minus 925 let's All right. Okay. Ready? Okay. So now I have an element with this electron configuration. Okay. So which block does this element belong to? Any other answers? Okay. Again what is block? Highest energy orital uh filled with electron. Okay. Let me add this uh uh when empty in case some of you got confused. Okay. So when empty which one is the highest energy? Okay. So it's P. So it is P block. Which group does it belong to? Any other answers other than 17? Why not seven? because seven is transition element. Okay, remember usually the groups, okay, we don't ask for transition elements, okay, we ask for main group. So again recap group, we look at valance electron in outermost shell. All right. So the outermost shell here is n = 5 the fifth shell. So copper electrons are seven. So if you look at your data book periodic table okay uh group seven is transition element so we don't talk about transition element so it is group 17 not seven okay it's 17 okay so identify this element it is in group 17 okay but we need another one information which is which period? So which period is this from? Five. Okay. So period is according to number of shell. So n= to 5 fth sh. So group 17 period five. What element is this? I uh so like this. Okay. So questions will come out in a application sense like this. You apply you understand what is period what is broke. Okay. And then what is block you identify the element. All right. Any question so far? No. Oh. Okay. So what is this now when empty? Okay. Because some student got confused teacher when I fill in with electrons let's say I have a 3d5 4s1 3d6 okay when I fill with electron 4s and 3d they will rearrange so when I rearrange 4s becomes highest energy arrange why is it still d block okay some students came and asked me just now during run time so that's why I add this when empty because when empty I know that according to 1 s blah blah blah blah blah and then I fill in 4s and then 3D so when empty 3D has a higher energy level so if let's say I have this configuration it is actually D block okay because my empty D has a higher energy level so it is D Okay. Any other question? Huh? Still don't understand because of your question. You see everyone don't understand. Just now everyone can understand. Okay. Okay. So there was a slight confusion just now some students. Okay. Let me write it but nicely. Okay, let's say I have this electron configuration 2 s2 2 p6 3s2 3p6 let's say 4 s1 3d5 okay so according to this configuration which block does this element belongs to which block yes it actually belongs to D block Okay. So why is it D block? Because when empty. Okay. When empty, I have 1 S, 2 S, 2 P, 3 S, 3 P. I fill in 4 S, then I fill in 3D. So when MP after 4s, I fill in 3D. When empty 3D orbital has a higher energy level that is why block is according to higher energy orital when empty. Okay. So when empty 3D has a higher energy level so it is the block. But the thing is okay I use another color. Okay. The thing is once your 3D because the energy level of 4s and 3D are very very close compared to all the others. Okay. They are very far away. 3D and 4s very close. So after I fill in 4s, I will fill in 3d. But as long as my 3d has at least one electron in there, you know, electron makes it stable. So when as long as my 3D has at least one electron, it will have a lower energy than 4. That is why I rearrange it like this. 32 3p6 3d5 42. So that if let's say I have to spawn a positive okay I remove electron from 4s because when they are electrons 4s now has a higher energy. Okay when 3d has electron they will rearrange 4s will then has a higher energy. So when I remove electrons I remove from 4s first the outer muscle okay digest this we are going to move on to something new okay yeah a lot of new things in chapter two okay so digest this first we are going to move on to ionization energy give you one minute okay I want to check uh attendance for a while. Albina Ayana right norm Amina stina. Okay. Nurali mirat profile. way heaven's name. Muhamad Abbar Muhamad Abar Muhamad Abbar. Oh, somebody has been signing for their friends. I want to remind students. Don't sign for your friend. What if your friend is being kidnapped? And you sign for your friend. We didn't know that your friend was being kidnapped because we thought that he was present in the class. You feel that it's very funny to sign for your friend. I know sign for him. You feel it's very funny. Please is very serious to sign for your friend. What if he's very very sick in the room and we didn't know he was very sick because he thought he signed the abandons and he end up suffering alone in the room. Okay. Please after this anyone to sign and we're going to really report the IO sending back to your country. Okay. Just I know not here. Oh no, not this. Missed earlier another month and Sansa. Okay. Okay. I hope the international students you don't feel bad because I'm checking your attendance. Okay. Just because your attendance is more than 30. Okay. In case you are not in the class, okay, it has to be reported. That's why I'm checking the international one specifically. All right. Hey, you're all done resting, done picking up oxygen. Okay, then we can continue. Okay, this is not something, okay? It's something quite logical just that it's something new, okay? But it's quite easy to digest. Okay. So we are going to talk about ionization energy. Have you heard of this word ionization when yes correct mass spectrometer which stage that's why I say everything in chemistry is related okay in the first of mass spectrometer. So what is ionization? Okay. uh become charged. Okay. What happen in ionization? Remove electron hit by high energy electron. Okay. What is the uh equation? Let's say I have X stickers and what I'm looking for X+ electron. Okay, so very good. So this is ionization energy. So what does energy means? Ionization energy is just means that I know I'm being hit by high energy electron. So how much of this energy do I need to become ion? Okay, so that is ionization energy. So how much energy is required to remove this one particular electron so that I become an okay so learning outcome end of the lesson. Okay. So as we have discussed and recap so we are talking about firing shooting heating high energy electron. Okay. So how much of this energy is needed to knock out that one particular electron is called ionization energy. So the unit is in kilogj per mole. Kilj is the unit for energy per mole. Per mole of what? What do you think is per mole of? According to the definition per mole of according to the definition per one mole of what? per one mole of electron removed. Okay, because ionization energy is uh energy has to be supplied to knock out one electron. So ionization energy is per one mole of electron removed. Okay. Okay. saw the equation we have also discussed Monday in gaseous state I'm going to form an ion I will remove electron so what is first ionization energy it means that the energy required to remove that first electron from gaseous atom okay to produce gaseous ion again and again and again. Will the definition come out? No, never. Okay. But I'm going to test application. Teacher, what do you mean by application? Okay. I'm going to ask you which of the following is correct regarding first ionization energy blah blah blah all the sentences. So you look at it. Okay. Maybe I'll say the energy required to remove one aquas atom. I didn't belong is incorrect because I want gases. Okay. So this is the definition of uh application question. Okay. Ionization energy normally is positive value because I need to absorb energy to remove the electron. Okay. So what is first ionization energy? Again the energy needed to remove the first electron from gaseous atom. Okay. Let's say I have carbon. Carbon has six electrons. All right. So I am divided into 2.4. So two in the inner shell, four at the outermost shell. So first ionization energy means I'm going to remove the first electron and where is the first electron removed outer most shell definitely from the outermost first okay so let's say I have second ionization energy I will remove the second electron okay now I want to test your understanding first ionization energy. The equation looks like this. Second ionization energy. I already give you a very big hint in the picture. Second ionization energy. What should be the equation? X plus dashes X2 plus Yes. All right. So ionization energy continues from the first. Okay. So the first one I have produced X plus. So when I want to remove the second electron I must continue from this X plus. Okay. test you how should I write third ionization energy very good produce X3 plus electron okay my next question carbon what is the maximum ionization energy for carbon how many of you say four any other answers Maximum ionization energy. What is ionization energy? Energy needed to remove electrons. Okay. So what is the maximum ionization energy for carbon? Okay. How many say six? It is this because ionization energy means you are removing electron. So maximum ionization energy is until you have finished removing all the electrons. So let's say we are talking about six ionization energy. Okay. So what is the equation for six ionization energy? Yes. Produce last electron. Okay. So questions can also come out in such a way which of the following represents the six ionization energy of X. So you have to know which one represents the six ionization energy. How to write the equation. Okay. Okay. Now I want to ask another question. Let's say I want to draw the graph. Okay. Okay. So this is the electron removed. Okay. And this is the ionization energy in kilogj. Okay. For carbon carbon. Okay. So some of you say four maximum four ionization energies. Why do you say four actually? Because there are four valence electrons. Okay. Let us try to plot the graph. Okay. The first electron removed. Do you think it needs a low or high energy? First electron remove low. Why low? Outer shell. We start from the outermost shell. Outermost shell usually is far from the nucleus. Definitely lower. Okay. What about the second electron remove? Lower. Higher or lower? Higher. Okay. because I have the same number of protons but I have lesser electron. Proton and electron what's their interaction between proton and electron what's the interaction between them what happen between them attract they attract so if I have same number of proton but I reduce one electron I can attract more okay attention just like I have this amount of lecturers but I have lesser students I can have more attention I can attract more. Okay. So when there's a lot a stronger attraction, I'll need a stronger energy. This is the second one. What about the third ionization energy? High or low? I four valence electron. Now I move on to electron number five. Where was it being removed from? Inertia. Okay. when it's being removed from an inner shell still follow this trend of general increase fifth ionization energy also like this what should happen to the fifth ionization energy sudden we say that suddenly there is a high increase in energy needle why is there a high increase in energy needle electron is removed from inner shell And what happened to inner shell? Closer to nucleus stronger attraction. Okay. So this is the same electron remover but the same electron continue jump or slightly slightly. Why slightly? Stain sh is still from the same sh. All right. Okay. So it brings us to this graph. Try to understand this graph. Okay. Let's try to interpret this graph. Okay. So we have learned the first ionization energy. Second ionization energy. Let's say we are talking about carbon. We have until six ionization energy. So all those after first we call it substep ionization energy. Substive means continuous ionization energy. Okay. So we can continue to remove electrons until there's no more electrons. I only have the nucleus. Electrons have finished removed. So we call this successive ionization energy. Okay. Now I want you to look at this graph. Let us try to understand this graph together. Which one is the first electron removed? Blue, red or green? blue. Why is it blue? Okay. And there's already an indicator, right? First ionization energy. Okay. So, I'll put a note here. So, this is the first electron removed. Why? because it has uh yes this is because it has the lowest ionization energy I is ionization energy. Okay. So what do you think about this trend increase? We say that increase gradually or you can say if this word is too difficult for you, you can say that small increase. What that does small increase shows you. Yes, very good. Electrons are remove right. I can remember sound. Okay. Electrons are removed from the same shell. So they have regular seame in Greece. Okay. Now I need to change the color. What does this means? Sorry. Okay. Okay. Um what do you notice about the trend first? This one you notice small increase. So what about this? Okay. We call it huge jump. Okay. Or we say that high increase. So high increase in ionization energy shows what? Yes. Electron removed from inner shell. You can use the word inner shell or you can say shell closer to nucleus. Sorry. It shall closer to Lucas and then the next trend. What can you say about this? Yes, you explain first. These are small increase. So it shows that they are yes removed from same shell. Okay. Actually the pattern are more or less. What you need to observe is the huge jump for ionization energy. The important thing is huge jump. Why we want to see huge jump? So that I know which one is removed from inertia. Okay. Again next this part. Yes. Huge jump. It shows that it is from inertia. Okay, enough about all the track. You can see the pattern already more or less the same. Now I want to move on to the next question. How many shells? How do you know there are three shells? Two huge jumps. Okay, there are two huge jumps and three grandable increase. Three small increase. So number of shells, there are three shells. My next question, how many valence electrons? Two or seven? How many will say two? Seven seven valence electron. Again, this is take note. All students take note 90% of the students get this wrong because of the same mistake. They thought this is valance electron. But always remember you know the first electron removed requires lowest energy. So you calculate from here you have seven electrons in the same shell. So there are seven valence electron. Which group? 17. Which period? What is the identity? Huh? Florine or Rome? Florine. All right. So questions are like this. Analyze. You analyze. not ask you to write essays I won't I won't ask you to write essays but you have to analyze this graph to know how many valence electrons which is the group what would be the identity okay what is the last one main shell electron configuration it means that the electron configuration ation using only the main shell. So how to write the electron configuration using only the main shell h 2 8 7 6 7 Okay. All right. Give you some time to digest it. Okay. So maybe secondary school level a lot of memorizing but foundation level is a lot of trying to understand trying to apply. Okay. Trying to analyze. We are not done yet. Still continuing. Okay. Digest this first. Can I go to another screen? Anybody still miss this? No. No. Okay. Close this. Okay, the last part of today I just want to do a little bit of brainstorming. Just brainstorming first. Okay, we won't go into how to write it first. Just the brainstorming part. Okay, so we will discuss one of the factors which affects the ionization energy. Okay, we know that ionization energy is the energy needed to remove electron. Okay. So what are the factors that affects the ionization energy? Okay. So the first factor we will talk about size. How does size affects ionization energy? Okay. So let's say if the size is big. So what happened? We have to do the explanation. Okay. So when size is big when we talk about ionization energy what is it that we have to consider the outermost shell how far is it and then we talk about force of attraction yes we have to know how strong is the force of attraction between nucleus and the electron okay so chinong is also right is also right so distance between okay the nucleus and the electron it's okay you don't need to write first tomorrow we will continue to write nicely okay so let's discuss when increase what happened to the distance between nucleus and electron okay what happened to the force of attraction then low so what happened to the ionization energy lower I need easier to ionize so I need a lower energy to ionize okay again it's a brain so I briefly write first don't worry tomorrow we will write nicely okay next a new nuclear charge what does the word nuclear reminds you of nuclear comes from where nucle okay not not not those no is the nucleus. Nuclear means the nucleus. In nucleus, what charge do you have? What charge do you have in nucleus? Plus because in nucleus you have proton. So nuclear charge means it is affected by number of proton. Okay. So if let's say I have high number of proton, what happen to the nuclear charge? Higher. More proton means more positive charge nuclear charge higher. So what happened to the force of attraction if I have more positive? Higher. What happened to ionization energy? Higher. Okay. And the last one shielding effect. Shielding effect means what is blocking? Okay. What is blocking between my nucleus and my electron? Okay. So what is in between nucleus and electrons nucleus and the electrons? I want to remove what are in between two things the diagram what are in between physically that you can see between the nucleus and the electron that you want to remove. Very good. Shell and electron all the other electrons right are in between. Okay. So since shell we have talked about size already. So shielding effect we focus on number of electrons. Okay. Let's say I have more electrons in between the nucleus and the electron I want to remove. What happened to the force of attraction? Okay, nucleus and I want to remove the electrons. Okay, if I have more I cannot see. So force of attraction is lower. When force of attraction lower, what happen to the ionization energy? Lower. Basically your specters are like this. Like I say, it's logical. You understand? Okay. So you just need to know how to write. Okay. So this one we will further talk about this tomorrow. Okay. So I'll link you to this. Uh it's exactly 10:00. So thank you class. I'll see you guys tomorrow. Okay. Thank you. Have a nice day.