LOK G LIVE | CLASS X (ICSE) | CHP 1 PERIODIC PROPERTIES

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[00:01:01]All IC students Take a deep breath.

[00:02:03]Yes, good evening my dear students.

[00:02:07]IC it is a IC class 10 students can join this class at 9 p.m.

[00:02:15]Class 10 IC students can join this live stream. This is for you myself. Yes, I sir your chemistry maths trainer. It is a course not a just a live stream. I'll be preparing you for the annual exam. And one thing IC students should remember is that to score good number of marks just reading is not sufficient. Reading is to understand the concepts in mind and then immediately you go on solving questions like I started last class the periodic properties we studied already the periodic properties atomic size then metallic character non-metallic character how do they vary along the period and down the group why they vary along the period and down the group up to four periods you must be Perfect.

[00:03:18]What is the first period? As per the ICC guidelines, you must know the elements periodic properties you have to study with reference to period 1, period 2, period 3, period 4.

[00:03:33]In groups, you have to take alkaly metals. Alkaly metals with reference to they have clearly mentioned in the syllabus with reference to alkaly metals.

[00:03:46]most electropositive and halogens group.

[00:03:49]In groups you have to remember these in the periods you have to remember first period. First period consists of only two elements hydrogen and helium.

[00:04:02]Second period starts from 1 to second period consists of lithium, berilium, boron, carbon. Right? Then you have oxygen, nitrogen, sorry, nitrogen first, 7, 3, 4, 5, atomic number 6, 7, 8, 9, 10.

[00:04:30]Only four periods you are expected from the board. Oxygen, florine, and neon.

[00:04:36]Don't go beyond fourth period.

[00:04:39]And third period starts from sodium.

[00:04:41]Atomic number 11, 12, 13, 14, 15. You must know their symbol. Atomic number clearly. 18.

[00:04:52]Now you have the elements here. Atomic number 12 will be magnesium. You must have clear understanding about it.

[00:05:01]Aluminium. 14 is silicon. 15 is phosphorus. And sulfur atomic number 16.

[00:05:10]17 is chlorine. 18 is argon inert gases.

[00:05:14]Last period four starts from atomic number 19 that is potassium.

[00:05:20]Right? And 20 you can take 21 starts here. 22 23 24 25 26 27 28 29 30 these 10 elements then up to potassium atomic number 19 20 first you make the elements perfect calcium fill in the blanks Here you must be very interactive right. You must have clear understanding of the elements in the periodic table.

[00:06:04]The elements 30 you have 31 32 33 34 35 36 completes the third period.

[00:06:16]Fourth period as per the as per the IC syllabus students must be perfect in fourth periods. You you need not go beyond fourth period only up to fourth period at least you must know the name of the elements. What is the name of the element with atomic number? 21 scandium and 22 is a titanium.

[00:06:42]Venadium, 23, 24 chromium, 25 manganesees, 26 iron, 27 cobalt, 28 nickel, 29 copper, 30 zinc.

[00:07:02]Next P block starts 31. N1 with atomic number 31 is gallium 32 germanium 33 arsenic and 34 selenium 35 bromine 36 krypton only up to these elements you have to make perfect. Yes. Good. Good evening.

[00:07:30]Good evening. Thank you. Thank you.

[00:07:33]Thank you for your comments.

[00:07:36]Thank you. Thanks for your everything.

[00:07:38]Thank you. Thank you.

[00:07:45]Okay.

[00:07:47]So see here as per the IC recommendation you have to know all these elements in the period four periods all elements at least atomic number and symbol you must be perfect then you have to know variations how the atomic size changes how the metallic character changes how the non metallic character changes you have to understand along the period first now you remember this thing atomic size I will give the theoretical concept again I will go to questions now what is my suggestion for IC students is most of the questions will not be lengthy for you but they will be tricky they will test your skill application ability therefore just studying book is useless and after studying the concepts concepts definitions you have Start answering the questions appeared in previous year or in text questions, end text questions, workbooks. Refer at least two to three books.

[00:08:57]Okay. And apart from your school books, I'll refer different books and give you atomic size.

[00:09:06]How does atomic size changes along the period? Atomic size along the period.

[00:09:10]How it changes and why it changes along the period. Before I start questions now my teaching for IC will be through questions.

[00:09:23]Okay. Once you learn the theory get ready for the questions. Along the period what happens? Atomic size decreases from left to right.

[00:09:34]Left to right.

[00:09:36]You must have clear understanding. It decreases.

[00:09:40]Why it decreases? We discussed in the last class. Again I will take questions and again explain you along the period decreases. Name the elements which particular elements have got highest atomic size. Highest atomic size will be alkaly metals that is group one elements.

[00:10:01]Group one elements. I'll drop this part.

[00:10:04]I think you noted up to 36 sufficient as per the instructions of the IC board only up to fourth period you must be taught in groups with reference to alkaly metals and halogens we have to study alkaly metals are placed in the group one let us finish the period now along the period atomic size decreases and you must now clear knowledge of why it decreases. Already we discussed in my previous uh videos, live classes, you can see it. Alkal metal start from lithium not from hydrogen. Hydrogen is a nonmetal. Lithium, sodium, potassium atomic number three. Sodium atomic number 11, potassium atomic number 19.

[00:10:57]Okay. Then you have ribidium.

[00:11:01]Rubidium 307, Rubidium, Cesium 55, transium radioactive alkaly metal it is not taken as alkal metal leave it only lithium, sodium, potassium, rubidium, cesium radioactive elements don't include them. Hogen start from florine.

[00:11:26]Atomic number nine. With reference to alkali metals and hogens, you are supposed to study down the group the periodic properties. Florine. Next you have chlorine. Atomic number 17. Next you have bromine atomic number 53. Next you have iodine.

[00:11:48]Iodine. Bromine. Sorry. Bromine 35.

[00:11:52]Because the next inert gases will be neon 10, argon 18, neon 10, argon 18. Then you have krypton sorry krypton 36, iodine 53 because 54 is zenon and only these you can remember. Iodine you have ain with atomic number atomic number 85 and 86 will be red on only remember them because you you you need not consider radioactive elements.

[00:12:34]So down the group what happens to the atomic size?

[00:12:39]Atomic size along the period along the period left right along the period decreases. Remember down the group down the group down the group atomic size increases in detail. We discussed about it.

[00:13:02]First periodic property we studied. You must know what happens first and why it happens. Next we discussed in detail.

[00:13:11]Just keep it in your mind. Second thing is called as metallic property to try to understand metallic property.

[00:13:22]So metallic property if you go along the period from left right along the period.

[00:13:28]If you take a first period, second period, third period, fourth period.

[00:13:31]Just now I explained you metallic property along the period.

[00:13:36]So metallic property meaning what?

[00:13:41]Metallic property meaning of metallic property is ability to readily lose electron. Tendency to lose electrons readily tendency to lose electrons.

[00:13:54]lose electrons and form positive ions and form positive ions that is M N plus metals.

[00:14:10]This is metallic property. This metallic property from left to right along the period goes on what along the period. What happens to the metallic property along the period?

[00:14:22]What happens to the metallic property and why it happens along the period? Along the period metallic property decreases, right? If you take as an example, period 3, period 2, you can take period 2 also you can take. The elements are lithium 3 4 5 6 7 8 9 10. If you take lithium, four is berilium, five is boron, six is carbon, 7 is nitrogen, 8 is oxygen, 9 is florine, 10 is neon. If you observe here lithium, berilium, boron are metals.

[00:15:13]If you come to carbon, nitrogen, oxygen and florine are called as nonmetals.

[00:15:20]Non-metals.

[00:15:23]Why this is happening?

[00:15:26]Why the why these particular lithium, berium, boron are metals?

[00:15:33]Why? Why the metallic property goes on decreasing from left to right along the period. And if you come down the group down the group these are alkali metals down the group what happens is metallic property goes on increasing.

[00:15:48]Remember metallic property this is along the period. If you take down the group alkaly metals down the group alkali metals you try to understand the concepts clearly.

[00:16:02]Metallic property. Metallic property remember increases.

[00:16:09]Remember increases down the group. Why this is happening?

[00:16:18]We'll try to understand it again.

[00:16:21]Atomic size you clearly I explained you and I want to clearly once again explain you why the metallic property changes and non-metallic property. What is the nonmetallic property? Non-metallic property is a tendency to gain electrons.

[00:16:38]See the third property we have seen is that non-metallic property.

[00:16:45]Non-metallic property. Carefully understand non-metallic property.

[00:16:52]The non-metallic property if you see along the period what happens? See this was metal. Metal these are pure metals.

[00:17:02]Lithium berilium metallic property boron will be less carbon is a total nonmetal nitrogen is total nonmetal oxygen nonmetal florine nonmetal neon is inert gas they are independent family they are chemically not reactive they don't involve in this particular thing therefore they are separate group and even you can take neon also nonmetal they are neutral so why this is happening non-metallic property propert what happens along the period what happens along the period non-metallic property along the period nonmetallic property increases remember down the group down the group down the group non-metallic property decreases we'll try to understand it logically they will not ask you the values But you are asked reasons.

[00:18:06]Let me explain you again by taking the two concepts.

[00:18:10]Why metallic property? I hope you understood these things.

[00:18:14]Remember correctly. Metallic property along the period decreases along the period decreases down the group increases. Reason why non-metallic property along the period along the period increases down the group decreases. Why? We try to understand logically. Look at here what happens.

[00:18:40]Let me explain you again. Just remember the concepts clearly. If the concepts are clear then you can answer the application questions carefully because most of the questions in the new pattern right so they are based on that why metallic property along the period look at here along the period metallic property increases down the group decreases metallic property increases sorry metallic property decreases decreases from left to right increases from down to group.

[00:19:23]It increases down the group increases down the group. Carefully understand why the metallic property decreases is observe here what happens to the atomic size. Atomic size what happens is from alkali metals if you continue atomic size goes on decreasing decreasing decreasing decreasing okay I'm not taking in particular any element just I want to show you atomic size if it is bigger see look at here here radius is still smaller still smaller radius is still still smaller smaller smaller smaller. Just logically you understand what happens when the atomic size is large means between nucleus and the valence electron is away. This electron in the valence cell is away from the nucleus means nucleus will have nuclear charge.

[00:20:30]Nuclear charge atomic radius will be highest and it will go on decreasing. See the distance between the nucleus and the outermost electron. What happens as the size is more this electron is more free more free. Just now I told you that metallic property is a tendency to lose electron. Suppose M is a metal.

[00:20:54]It's a metallic property depends upon how many electrons it can lose. Suppose that it it readily loses n electron.

[00:21:02]This becomes m n plus plus n electron.

[00:21:05]So say you can take sodium. Sodium becomes Na loses one electron and forms readily loses one electron. Liberates one electron. Therefore it is highly reactive and pure metal. Highly metallic property. Highest metallic property is observed in group one metals.

[00:21:23]They are highly reactive metals means more the ability to lose electron. Why is sodium placed in the group one alkaly metals readily lose? Because their size is big means the distance between the nucleus and the outermost shell is more.

[00:21:38]Therefore this electron by by supplying little energy if you supply little energy little energy you can remove it. Therefore at the room temperature in the cold condition only sodium when put in water it it readily reacts. Therefore sodium metal is stored in kerosene not in water. You cannot put it in air. It is a gray colored metal stored under kerosene can be cut with the knife.

[00:22:07]Why this happens? Because this sodium in the valence electron is far away from the nucleus. Therefore control of the nuclear charge positive charge influence of the effective nuclear charge influence of influence of nuclear charge is less.

[00:22:25]Therefore electron can be easily removed. Now see like parents yesterday I gave you example parents and students or teachers and the students and the distance between the parents and the students is more then the students become what more free they do whatever they want.

[00:22:48]If they are very close under the control of the parents then uh to remove this particular uh student for a movie to take your friend to a movie you can easily take if it is away from home staying in some other place. Now as the as the size decreases along the period this outermost electron comes closer and closer to the nucleus. Therefore this influence of nuclear charge on on the electron goes on increasing. Therefore you need to require more energy. Suppose that you need to you have to supply 10 J here. Sorry. Suppose that you want to supply five J to remove this electron.

[00:23:30]Here electron required to remove maybe 10 J. More energy is required because it is under the control of the nucleus. And as you move further further further the nuclear charge influence will go on increasing. See because one proton increases nuclear charge is increasing increasing increasing and therefore they will pull the valance towards themselves.

[00:23:55]Therefore they are under the more control more control. Therefore to lose electrons is difficult.

[00:24:03]That is the reason as to why metallic property decreases from left to right.

[00:24:07]Lithium is a metal.

[00:24:10]Berlium is a metal. Boron is a metal but carbon is a non-metal. Nitrogen is nonmetal. Oxygen is nonmetal. Florine will have still a smaller size and suddenly inert gases becomes larger size.

[00:24:29]You can observe I explained in the last period.

[00:24:32]I hope you are understanding the meaning.

[00:24:35]Therefore these metals particularly lithium, berium, boron are metals because the distance between the nucleus and the outer shell is more. Therefore the electrons can be easily kicked out by supplying little energy. Therefore they have tendency to lose electrons after carbon nonmetals will begin.

[00:24:56]Right? So metallic property goes on decreasing along the period.

[00:25:00]I hope you understood.

[00:25:03]Similarly, what happens to the nonmetallic property?

[00:25:08]Non-metallic property increases. What is the nonmetallic property?

[00:25:12]I will take non-metallic property.

[00:25:15]Carefully understand. I will try to clear you the concepts. If your concepts are not clear, you can ask me the doubts.

[00:25:26]Non-metallic property. Observe here.

[00:25:28]non-metallic property means tendency to gain electrons and the meaning is that these are givers givers of electrons donors of electrons but these nonmetallic nonmetals are they are acceptors acceptors of the electrons they have tendency to gain electron tendency to tendency to gain electrons gain electrons. For example, if you take the nonmetal florine, right? Florine can gain one electron and form a fluoride ion.

[00:26:10]Oxygen gains two electrons and form oxide ion.

[00:26:17]Nitrogen gains three electrons and form a nitride ion.

[00:26:24]Carbon can gain four electrons and form a carbideion.

[00:26:29]Look at here. And lithium has got tendency to lose electron. Berium has got tendency to lose electron. Even boron can have the ability of both lose electrons.

[00:26:41]Right? These are nonmetals have the tendency to gain electron. Why do they mean non-metallic property goes on decreasing along the period. Decreases along the period. Sorry. A metallic property decreases and non-metallic property increases along the period. Try to understand what why it is increasing.

[00:27:00]Logically you try to understand.

[00:27:03]Now what is happening here is nuclear charge is more more goes on increasing goes on increasing means what this nucleus will have a ability due to the nuclear charge can hold an extra electron on it because nuclear charge will have the ability to gain and hold extra electron on its surface. Therefore observe florine can gain one electron because of the nuclear charge is more positive charge of nucleus there is nuclear charges nuclear charge is more due the effective nuclear charge is more these elements say that is carbon you can take carbon nitrogen oxygen florine and their atomic size is also less and nuclear charge is more therefore they have got ability carbon has got ability to hold four electrons. Nitrogen has got ability to hold three extra electrons.

[00:27:59]Oxygen has ability to hold two more extra electron. Florine has ability to hold one more extra electron. This tendency to gain electron increase because effective nuclear charge increase in the effective nuclear charge will have the ability to gain electron and hold it. But these do not have that ability metals. Therefore, this non-metallic property increases from left to right along the period. I hope the metallic and non-metallic property concepts are clearer to you, my dear students. You try to understand these concepts clearly.

[00:28:35]Okay. Now we'll see down the group. Down the group, let me clear you. What I told is metallic property is the tendency to lose electron. Non-metallic property is a tendency to gain electron from left right along the period. The reason for this is left right along the period atomic size goes on decreasing nuclear charge goes on increasing.

[00:28:59]See as a distance with the nucleus and outermost shell is less. In case of the metals lithium, berilium, boron, these electrons by they have tendency ability easily they can lose electrons.

[00:29:14]Means this reaction of losing electron is called as oxidation.

[00:29:18]Gaining electron is called as reduction.

[00:29:20]We studied in earlier oxidation reduction. Later we'll talk about it.

[00:29:28]See this is the thing and they have tendency to look as you move further what happens is metallic property goes on decreasing because the electron cloud will come closer and closer nuclear force will increase like a parents will be very very close to the students. Therefore students are tightly bound to it and therefore they cannot be lost easily. And if you see non-metallic property tendency to gain electron it increasing along the period why as you move further if you come to your carbon nitrogen oxygen florine due to the increased nuclear charge the decreased atomic size nuclear nucleus can hold extra electron on it if the electron is donated by some other element they have ability to hold the electron so therefore this tendency to gain electron is called as a nonmetallic property.

[00:30:22]Therefore, non-metallic property is increasing along the period. Metallic property is decreasing along the period.

[00:30:30]I hope concepts are clear. What happens down the group? That one I will explain you clearly today. So next period again we will solve attempt questions. You start solving in text questions, end text questions. How many questions you attempt that that is very very important answers are not lengthy very short answers test your skill and application and understanding. So down the group what happens? See down the group what happens is at every period first period second period third period fourth period if you take we take we are interested in only fourth period what happens new cell is introduced here how many cells are there suppose I take this one as nuclear charge and only one cell is there in the first period what happens in the second period in the second period what happens is K cell and L cell two cells are introduced what happens in the third period we are interested in only but nuclear charge will also increase. Size also increases. Here third cell will have how many cells? It will have three cells. Are you getting me? Let me draw smaller. Here only K cell will be present. Here in the second cell what will be there? It will have K cell as well as L cell. If you come to the third period, it will have nuclear charge will be more more but cell one 2 three sudden increase in the cell. If I take a four cell it will be further more it will have four cells.

[00:32:10]Fourth period one this is K cell, L cell, Y cell and N cell. Observe carefully down the group if you go what is happening to the size?

[00:32:24]Size is suddenly increasing means distance between the nucleus and outermost shell. Distance between the nucleus and outermost shell. Distance to the nucleus and electron in the outermost shell is increasing more and more means students are going more and more away from the from the parents.

[00:32:45]What should happen? If I take down the group lithium, sodium, potassium, sodium, potassium, rubidium and cesium. This is present in second period, third period, fourth period, fifth period, sixth period.

[00:33:03]Now size is continuously increasing means as the size increases average distance between the nucleus and the electron is less here more here much further more most here means the electrons becomes more and more away from means little energy is required to remove cesium right and here lithium to cesium if you come what happens distance between the nucleus and the outermost shell increases. Therefore, lithium sodium can more readily give sodium can more readily it is more metallic than more metallic than lithium. Potassium is more metallic than sodium. Rubidium is more metallic than potassium. Cesium is more metallic than rubidium. Therefore, cesium is most metallic property. What the decreasing order of metallic property? Cesium is greater than rubidium. Rubidium is greater than potassium. Potassium is greater than sodium. Sodium is greater than lithium.

[00:34:06]This is the decreasing order or decreasing order of metallic property. Therefore, down the group down the group down the group down the group metallic property down the group down the group. Yes.

[00:34:24]Metallic property increases. Note it correctly.

[00:34:31]Metallic property increases down the group only reading is not sufficient.

[00:34:35]Thinking is important. Why? Why? Because distance between the nucleus and electrons larger the distance easier will be the electron to give out.

[00:34:46]Therefore, cesium most readily gives electron. Rubidium will be less than cesium. This is called as electropositivity.

[00:34:55]Cesium has got highest. Next comes rubidium.

[00:34:58]Next comes potassium. Sodium, lithium.

[00:35:01]Therefore, metallic property is like this means metallic property down the group goes on increasing.

[00:35:08]Now what happens to nonmetallic property? What happens to non-metallic property?

[00:35:16]Non-metallic property. What is the nonmetallic property? Just now I told you that nonmetallic property is the tendency to hold the electron. Say if an extra electron now as you move down the group the distance between the nucleus and the outermost electron electron is more means this nucleus has no control over the its own electron then how it can gain extra electron and hold it. I hope you are getting me. If a parent cannot look after his or her own child, how it can adopt any other child?

[00:35:51]No, that capacity will not be there.

[00:35:53]Therefore, non-metallic property, it has no ability because of the distance.

[00:35:58]Nuclear charge will have no influence on it. Therefore, non-metallic property decreases.

[00:36:04]Understand clearly.

[00:36:07]Non-metallic property decreases.

[00:36:09]Metallic property goes on increasing.

[00:36:11]Even you can take the H hallogens.

[00:36:14]Hogens if you take florine, chlorine, bromine, iodine. Let us take a come down the group what is happening?

[00:36:25]New cell is introduced.

[00:36:27]Means the size of florine will be less, chlorine will be more, bromine will be still more, addin will be still more, aatine will be still more. What happens?

[00:36:38]What happens? the nuclear charge atomic size will be more then nucleus will have less ability to hold the electron right so if I want to write correct decreasing order of the nonmetallic property which has got highest nonmetallic down the group if you say which is decreasing order of the metallic nonmetallic property nonmetallic property which is most nonmetallic florine is more than what chlorine why atomic size is more therefore its ability to hold the electron will be less. Bromine chlorine has highest nonmetallic property. Chlorine next comes bromine.

[00:37:20]Next comes iodine. Next comes a statin mean down the group. What happens is metallic property goes on goes on decreasing.

[00:37:29]This is called as decreasing order of non-metallic property.

[00:37:35]Decreasing order of nonmetallic property. You will be asked in MCQ non- metallic property. I hope you understood the concepts my dear students. I hope I have cleared you the concepts that is three per periodic properties we completed. One is atomic size. Second one is metallic property in detail I have discussed today and next one is nonmetallic property. Next period I will come with more questions. more questions, tough questions, application questions on these three properties.

[00:38:09]Then we'll continue with the two more properties. One is ionization potential, another one is electron affinity. If you study that the chapter will be completed, then we'll have a test. Okay, tomorrow I will remind you carefully.

[00:38:25]Tomorrow is a mathematics last combined class. Then mathematics class will be separated. CBSC state and CBSC will be one batch. ICS will be at your own batch. Tomorrow one period test between 8 to your class is between 8 to 9. I will send you paper at 7:00 p.m. Please note it tomorrow.

[00:38:53]Trigonometry test. Trigonometry.

[00:38:56]Trigonometry test.

[00:38:59]I will write this note down correctly.

[00:39:02]Don't get confused. I will put it in the WhatsApp group also. Trigonometry test.

[00:39:09]So in the WhatsApp group I will send you test paper. Mathematics subject is trigonometry 20 marks and 45 minutes test will be there covering up to identities trigonometric identities trigonometric ratios standard angles study them correctly and identities trigonometric identities on that we solve problems between 8 to 9 combined we are taking tomorrow is the last combined class then I will separate the classes see uh the time is at in your WhatsApp group that is log IC WhatsApp group I will send the paper at 7:30 p.m.

[00:40:01]PDF I will send you PDF you have to in the long seat you have to solve I will come live at 8:15 8:15 p.m. to 9:00 p.m.

[00:40:16]There will be evaluation that is discussion, discussion of the paper and self assessment. You have to do self assessment without cheating.

[00:40:30]Self assessment of the paper. Then you have to send your marks in the group.

[00:40:37]Join WhatsApp group. Links are available in the WhatsApp only. I will send the PDF at 7:30 p.m. Right? Then at 8:15 to 9:00 p.m. I will discuss the paper along with schemaation. Then you can make the self assessment.

[00:40:55]I will go on giving you schemaation. You solve them and uh self assessment. At the end you have to upload the marks. After tomorrow class maths period will be separated right like a chemistry period now right? like like chemist 9 to 9:45 will have mass period and uh as usual 9 to 9:45 no combined class this is the last combined test after that I will separate the classes then again I will combine okay we'll continue in the next class tomorrow write the test I'll give the details in the WhatsApp okay if you like log zi classes my explanation please subscribe Ask your friends, relatives and uh uh anywhere let them join as in the live stream actively participate here. It is not a YouTube channel. It is a course. I am not a YouTuber. I am your teacher. You are not my subscribers. You are my students. That's all my dear students. Bye-bye. See you tomorrow. On the best for the