hello my dear friends I am shubham from learnhob the free learning platform where you can study Physics chemistry math biology absolutely for free at learnohub.com so then let's start [Music] so friends we are going to start with the new chapter in this video Chapter number two chemical bonding yes we have completed your first chapter and in this video we are going to study all the concepts of ionic bonding after that we are going to solve some questions so without wasting much time let's start and let's rock so friends before starting to learn this chapter the first and the foremost question which should arise in your mind and in the mind of every student before learning any chapter that why we should study that particular chapter right so why study chemical bonding now you would be seeing on the screen there is solved right you would have guessed it right and this salt the table salt NaCl we use it every day okay our mummy uses its for cooking food and without this salt our food would taste like hell right it won't taste good absolutely now let me tell you an interesting thing about this salt if you want to boil this salt or if you want to First melt this salt okay so you have to heat it to 800 degree Centigrades so this means that its melting point is 800 degree centigrade and if you want to boil the salt you have to heat it till 1400 roughly around 1400 degree Centigrades now it's boiling and melting points are so high right now why on this Earth a simple chemical compound like salt has so high boiling and melting points right we want to know the answer so for that you need to study chemical bonding and like this we would see the answers of so many interesting questions so I'm definitely sure that you are feeling convinced and excited so then let's start so friends I know that you have studied chemical bonding in your previous grade ninth grade as well right and in ninth grade you have studied the basics of chemical bonding and the basics of ionic bonding and covalent bonding along with the orbit structure diagrams of ionic compounds and orbit structure diagrams of some covalent compounds and covalent molecules right now what we are going to do we are going to just quickly go through quickly revise the concepts which you have learned in your ninth grade okay the basics of ionic bonding and the basics of covalent bonding and then we are going to get into the Crux of this chapter which is the electron dot structures of ionic compounds and then we are going to study the properties of ionic compounds okay in case of ionic bonding and when we are going to study the covalent bonding we are going to again go through the basics of covalent covalent bonding okay we are going to revise it and then we are going to see the Crux of covalent bonding which is the electron dot structures of covarent compounds and covarent molecules and the properties of covarent compounds okay and lastly you would be introduced to the third type of chemical bond which you haven't studied in your previous grid which is coordinate Bond okay very interesting type of bond and yes just the basics and some compounds we are going to study the formation of some compounds in case of coordinate bonding as well okay so now let's start with chemical bond itself okay let's start revising the basic concepts so I know I definitely know you all know the chemical bond but let's just brush up the basics so chemical bond is actually a force of attraction right force of attraction or attractive force between the constituent particles okay and this constituent particles can be atoms or it can be ions okay and this attractive Force okay it is holding the constituent particles right together it is holding the constant particle together in a chemical species okay so if the constituent particles are atoms so the chemical species would be molecule okay if the constituent particles are ions okay which are being held by this attractive Force okay then the chemical species would be the ionic compound okay so this attractive Force which is holding the atoms or ions okay together in a molecule or in a compound is called the chemical bond okay very simple now we already I have already introduced you to the three types of chemical bonds now let's first start with I only want the basics of ionic bond so let's quickly revise ionic bond and ionic compound so any ionic bond is actually a chemical bond which is formed due to the transfer of electron or electrons okay from now this is the important thing from the atom of an element okay so I'm taking suppose sodium so the bond which is formed due to the transfer of electron okay so this is the outermost shell of the sodium atom so transfer of electron from the atom of an element so this is atom of sodium element and here the electron is getting transferred to the atom of another element okay so here comes our villain okay this is the hero this is the villain and this is accepting the electron the chlorine atom is accepting the electron and the bond which is formed due to the transfer of electron from the atom of an element to another to the atom of another element okay is called as ionic or electrovalent Bond very simple and what is ionic or electrovalent compound we already know the compound which is formed due to the transfer of electrons right from the atom of an element same same thing the compound which is formed due to the transfer of electron from the atom of an element to the atom of another element okay so that compound is called as electrovalent compound or electrovalent or ionic compound next is electrovalency okay so what is the electrovalency of an atom of a element okay so it's simply the number of electrons the particular that particular atom of an element loses or gains to form loses or gains to form ionic bond okay that's it that's it so let's apply this concept quickly I am taking an example of any compound any cell we all know okay so what is the electrovalency of sodium here in this case and what is the electrolysis of chlorine here in this case very simple we all know that sodium loses one electron okay so yes we just now saw the number of electrons an atom of an element loses or gains so it is losing one electron to form the ionic bond right so this means the electrovalency of sodium is one similarly chlorine is accepting that particular electron so it is gaining the one electron to form the ionic bond so this means that chlorine has electrovalency one now try to calculate the electrovalency of mgcl2 okay don't go it don't make it wrong okay you can pause the video right here and then you can check the answer okay so mg here it donates two electrons right or loses two electrons to form the ionic bond so its electrovalency would be two but the these two electrons are accepted okay by two chlorine atoms right so what we can see about the chlorine here chlorine would have the electrovalency one one because the atom of chlorine accept only one electron to form the ionic bond right to form the ionic bond so that's why its electrovalency would be one it would not be 2 okay so interesting now let's see the conditions for the formation of ionic bond okay so very very simple simple conditions are there okay three conditions and we can just remember them with the help of the concept of ionic bond itself so we know what happens when the ionic bond is formed one of the atoms loses the electron and another atom okay gains that very much electron okay it may lose one or more electrons and the other atom gains one or more electrons okay so it depends on the compound which is getting formed but the major concern is the main concept is one atom loses the electron another atom gains up the electron so there is an electron transfer right and after this electron transfer ionic bond is formed now this means that one atom should definitely have the tendency to easily lose the electron right this atom should have tendency to easily lose the electron now how we can express this tendency okay in terms of ionization energy so if this atom has tendency to easily lose the electron this means that we can say that it is having less ionization energy why because this means that less energy is required to remove the electron so if less energy is required to remove the electron it easily loses the electron correct so one of the atoms should have low ionization energy very simple now same way the other atom should easily gain the electron that should be our major concern so if the other atom should easily gain the electron so this means that how we can express the this ability in terms of electron affinity so it should have high electron affinity that's that's when it would easily gain the electron okay the affinity for the electron should be very high so other atoms should have high electron affinity then only it would easily gain the electron and the third condition is the atoms of different elements we know ionic compounds are formed between the atoms of different elements right now between the atoms of the different elements the electronegativity difference should be large okay now we would learn this we would learn the reason of this concept in your higher standard but for now you have you just remember one thing you just understand this concept by one thing that when the electronegativity difference is very large the electron transfer becomes easier okay and what else we want to form an ionic bond we just want that electron transfer should be very much easy so ionic bond would be easily formed so these are the three conditions okay now based on these three conditions we can clearly make out that see the ionic bond would form between metal and a non-metal right how I'm saying this thing just try to match the conditions see the metal the atom of the metal would have low ionization energy yes because metals have low ionization energy we have studied in the first chapter similarly the atom of the non-metal would have high electron affinity correct we have also studied this in the first chapter and the third condition the atoms of different elements should have large electronegativity difference so we all know that metals have very low electronegativity while non-metals have very high electronegativity right that's why we call them as electronegative elements and we call Metals as Electro positive the opposite of electronegative right so this means that if they are having low electronegativity if non-metals are having high electricity then the electronegativity difference between metal and non-metal would be definitely very high would be definitely very large and that's the reason ionic bonds are formed between metals and non-metals okay so this can be the question which which this question could be asked in your exams very simply ionic bond can be formed between metals and non-metals okay so Dash and dash it would be a fill in the blanks or it can be anything okay a one-liner answer as well so friends till this point we have revised all the basics of ionic bonding okay now let's move on to the main Crux of this chapter which is the electron dot structures of ionic compounds okay we are going to see the electron structures of NaCl mgcl2 and calcium oxide but before that let's first see how to draw an electron dot structure okay the basics of electron structure you have to just remember this three simple rules to draw the electron dot structure and then you can draw the electron dot structures of any compound okay so let's start first learning how to draw an electron dot structure so if I have to draw the electron dot structure of an atom okay so the first rule says that you have to first write the symbol of the element okay of that particular atom so I have to draw the electron receptor of oxygen atom then I would just first write the symbol of oxygen okay then I will represent okay then the rule is saying that you have to represent the outermost shell electrons okay with the help of dots so there comes the name electron dot structure okay so the outermost shell electrons of oxygen I have to represent with the help of dots so I know Oxygen's outermost shell has six electrons from its electronic configuration we can get this thing now before representing the outer motion electrons with the help of dots let's move on to the second rule because it tells us how to represent okay the second rule says that paired electrons should be represented by a pair of dots unpaired electrons should be represented by single Dot okay so what we would do we would first pair up the electrons so one two three four five six so I have paired up with six electrons I have three pairs now how I would represent this very simple we have to not create the mass of electrons okay around the symbol so that what I would do I would just represent one pair on the one side second pair on the other side third pair on the third side don't do in this way okay here only you are just representing the pairs on the same side or like side by side to each other okay represented on different sides so it would be neat and clean okay and it would be easy to understand as well now how I would represent the unpaired electron then with the help of single dots so let's take an example of fluorine here okay so fluorine has electronic configuration 2 comma seven so I would again pair up the electrons so six electrons would be paired in this way I have three pairs and the last electron seventh electron would be unpaired so in the same way just like oxygen I would arrange the six electrons in the three pairs on three sides and the last unpaired electron with the help of single dot on the last side okay so in this way you have to represent the outermost shell electrons in case of atoms now third rule is used our third rule would be helpful for us when we are drawing the electron dot structures of molecules so suppose I am having these two molecules HCL and cl2 okay now the rules States us that it's very simple when we are representing the outermost shell electrons okay of the atoms okay of a particular molecule so if the atoms so this the rule is saying that you have to use different symbols for the different atoms okay in the molecule so I would use if I'm using dot for hydrogen then the rule says that use either circles or Cross or the other atom for representing the outermost electrons of the other atom so then I have to use cross okay same way if I am using dot for this chlorine atom I have to use Cross or Circle for the other chlorine atom okay but when we are drawing the electron dot structures in case of a molecule okay which is made up of the atoms of same element okay here in this case is chlorine so you can either what you can do is you can represent the outermost shell electrons with the same symbol as well okay so what I suggest to you is in case of a molecule then when it in case of a molecule which is made up of atoms of same element use same symbol okay very simple and in case of a molecule which is made up of atoms of different elements use different symbols now this you should keep in your mind you should never forget this okay so for that let's make it simple so I told you to use the same symbol for the molecule having atoms of same element so it would automatically remember that oh I have to I have to use different symbols for the molecules having the atoms of different elements okay okay so now let's see the electron dot structure of NaCl now I know in the previous grade you have studied the elect the orbit structures of NaCl mgcl2 and calcium oxide so I pretty know you have a basic idea how these compounds are formed but in order to draw the electron dot structure as well we have to first understand how these compounds are formed okay so we will quickly go through the process how NaCl is formed and then you would be able to draw the electron dot structure of any cell very easily so we know it is made up of sodium and chlorine atoms now the same logic sodium has one electron in its outermost shell okay from its electronic configuration we can find out and chlorine has seven electrons in its outer motion okay now sodium wants to get rid of its one electron anyhow so that it would attain the configuration of neon electronic configuration of neon which is the nearest noble gas to sodium okay it is having configuration to commit so after getting rid of this one electron it would have the electronic configuration to commit so what it does it just loses that one electron and forms any Plus which is having the electronic configuration two comma it same as that of the neon the nearest noble gas okay same way now what chlorine does chlorine just takes the chance chlorine atom what it does it just picks up this electron which is lost by sodium okay now it's very good chance for the chlorine once it picks up this electron its outermost shell gets filled eight electrons and it attains the electronic configuration of the nearest noble gas to chlorine which is arrogen okay 2 comma 8 comma eight now it accepts the electron but it forms CL minus in this case okay now this CL minus and any plus now these are charges this is a positive charge negative charge so we know like charges repel each other unlike charges attract each other so in this way they they find an affection for each other okay so they just attract each other and there develops a strong electrostatic force of attraction between them okay now you have to remember this word because it is a key word strong sorry electrostatic foreign okay develops between the n a plus and cl minus and this results into the formation of ionic bond okay and the compound NaCl ionic compound is formed so this very story you have to just represent with the help of electron dot structure as simple as that okay so I'm having this any so what what we have learned first we have to represent the electron dot structures of individual atoms okay any and cl then how they are combining they have to show and then we have to show the compound initial so first any I have written the symbol then the outermost shell electrons I would represent it with the help of dots right or circles or crosses any one symbol you'd pick so I I like DOT first so I have represented the outermost shell electron of sodium which is one with the help of one dot then comes chlorine in the picture so chlorine has seven electrons so what I would use now now I cannot use the dot right you remember I have told you when you are using the representation the symbols for representing the electrons if the atoms are of different elements use different symbols if the atoms are of same element use same symbols so these are the atoms of different elements use different symbols simple so I would represent seven electrons in this way one two three four five six and seven okay seven crosses now what happens we know this sodium atom is losing this electron chlorine is picking up this electron and what is getting formed in ACL so how inacial is formed after losing this electron n a becomes n a plus so we would just write n a plus here okay no electron now to show here in the compound and chlorine picks up this electron so chlorine will have its own seven electrons this way and the electron of sodium would come here okay so big so so now eight electrons there in the outermost shell of chlorine it's very much happy but being happy it is also getting a negative charge don't forget to show the charges okay in the ionic compound which is formed when you are drawing the electron dot structure so simple that's it any plus CL minus and this is your electron Dot Structure for any CL so in examinations they directly give you the atomic numbers and they ask you to draw the electron dot structures so simply you have to draw the structure by remembering how an ACL is formed so that you won't make any mistakes okay this arrows this charges are the small things which you would forget while drawing the structure then you would miss the marks next is mgcl2 magnesium chloride so same way how sodium chloride is formed magnesium chloride also has the same type of story okay but there is slight twist very slight twist so first electronic configuration two command comma two it has two electrons in the outermost shell okay this magnesium wants to get rid of these two electrons so that it would have the electronic configuration of neon and it would become stable okay this is the nearest noble gas to magnesium so it gets rid of its two electrons and it forms mg2 plus which is having electronic configuration of neon very well clear now same story for chlorine two comma 8 comma seven right seven electrons it is in just need of one electron so that it would gain so that it would complete its octave become stable and attain the electronic configuration of argon okay but what is happening here see magnesium is giving up two electrons okay and our poor chlorine can only accept one electron it cannot accept more than one electron anyhow so what it does it tells another chlorine atom he calls his another brother UC in this way please come please help me in gaining the electrons given by magnesium so what what you do is I will gain one electron you gain another electron so in this way both of them would use these two electrons so this electron is gained by this chlorine suppose and this electron is given by this chlorine atom so what would happen after gaining the electron it would become CL minus here also it would become c l minus so we are having two CL minus ions and one mg two plus sign so see the charge is 2 plus and the total charge is minus minus so minus 1 minus 1 it's minus two so two minus right so it's getting balanced so in this way the two electrons which are lost by magnesium are gained by two chlorine atoms and two chloride ions are formed so there would be an strong electrostatic force of attraction between this mg2 plus and this two CL minus ions okay and it would result into the formation of ionic bond and the ionic compound mg cl2 okay since there are two elect two chlorine atoms so CL very clear now we have to just show this process with the help of electron structure so what I would do is I would first write mg then it's two electrons so I would represent it with the help of dots okay what would happen I am having chlorine atoms but I am having two chlorine atoms right so same way seven electrons seven electrons okay now we know this thing we have drawn the structure of inacial seven electrons of both the chlorine atoms now this electron here it goes to this chlorine atom as we have seen in the story and this electron is going to this chlorine atom okay so here it is very important to show two arrows okay because two electrons are going to different because each electron is going to the different chlorine atom and what happens [Music] mg2 plus is formed right and this two chlorine atoms by gaining two by gaining electron okay this is gaining this one electron this chlorine atom is getting one this one electron so what I would do is I would show just a single chlorine atom okay and I would just write 2 in front of it so this would represent the two chloride ions okay here foreign is formed right it's just the same like NaCl so here the CL minus ion not one there are two CL minus ions right right in this way this is one cl minus sign and after accepting the electron this is the another CL minus sign so what I have done is I have represented this both of the CL minus ions by writing just 2 in front of them and showing the chloride minus I okay so this becomes our mgcl2 [Music] and this is the electron dot structure of mgc2 no need to draw this chloride ion separately I have just drawn it to show you in exam you have to draw this structure okay just don't forget to show the arrows and the charges and you won't forget if you would remember the process so that's why I'm telling you to just remember the process and then you would easily draw the electron dot structure okay now moving ahead to calcium oxide what I would suggest to you is you pause the video here and you try on your own to write the electron dot structure of calcium oxide okay it's very simple and once you have written just un just resume it so that to check the answer okay whether you have drawn the right electron or structure or not okay so let's start so calcium same way 2 comma 8 comma eight comma two okay so it is having two electrons in its outermost shell so you just want to get rid of that two electrons so it would attain two comma eight comma eight electronic configuration of argon so it just gets rid get rid of that two electron and it becomes ca2 plus okay stable now this two electrons which are lost who is in front of calcium oxygen right in calcium oxide now oxygen has two comma six electronic configuration so it is in very much need of just two electrons and here calcium gives the two electrons so it it would be half it would happily gain these two electrons so it is doing the same thing it is gaining these two electrons and its electronic configuration would become two comma eight same as that of the neon so it would be happy now stable but after gaining this two electron it is developing 2 minus negative charge okay now this cf2 plus and O2 minus see the charges are getting balanced 2 plus 2 minus now there would be a strong electrostatic force of attraction between them ionic bond would be formed and ionic compound calcium oxide is formed right now we have to just represent it with the help of electron dot structure very simple calcium okay two electrons in its outer motion so I would just draw here two dots then oxygen okay so here oxygen is having six electrons in its outer motion so one two three four five six different symbols okay do not forget now this two electrons are going here in this way so show it with the help of two arrows either show two arrows or you can show just one Arrow as well but then right on that Arrow two electrons okay very important so because of the small things you would lose the marks now these two arrows are showing these two electrons are being accepted by oxygen what what is happening next calcium would become ca2 plus after losing two electrons right oxygen it would become 2 minus okay O2 minus ion oxide ion so this two electrons are here okay now I will just put it in the bracket and in this way so ca2 plus and o two minus so you have to just draw this structure and this is the electron of structure of calcium oxide okay so moving ahead the next topic is properties of ionic compounds we have completed the electron dot structures of all the three ionic compounds NaCl mgcl2 and calcium oxide now first property is constituent particles so ionic compounds are made up of which consonant particles very clear we know it very well n a plus CL minus mg2 plus CL minus calcium oxide ca2 plus and O2 minus what are these These are ions right so yes their constant particles are ions now state of existence so how they exist so RNA compounds exist in solid state and these are hard solids okay now let's know the reason of this why they are in solid state and why they are hard enough so we know that when the ionic compounds are formed what what is happening the strong electrostatic force of attraction is being developed between the ions right strong electrostatic force of attraction and that's when I told you you have to remember this this is a keyword okay here if you would miss electrostatic or force or attraction any any of the word then it would not sound the same thing it would not mean the same thing so the strong electrostatic force of attraction is developing between the ions and because of this very much strong electrostatic force of attraction what is happening the ions are held very much closely to each other okay very much closely and very much strongly okay so now we know that when the constituent particles are held very close to each other and very strongly to each other so in which state that particular compound would exist or that particular chemical compound would exist in yes right solid because we know solids are like closely packed right in this way this is like this and they are hard enough because the force of attraction between the ions is very strong so we cannot like break them easily okay very clear next property is boiling points and melting points so ionic compounds have very high boiling points and very high melting points now comes the answer of the very first question from which we have started right that why a very simple chemical compound like NaCl is having so high boiling point and so high melting point like its melting point is 800 degree Centigrade while boiling point was like roughly around 1400 degree Centigrade so why is this so and I have told you that we would discover this answer when we would study chemical bonding and here we are okay so the reason behind the high melting and boiling point of the ionic compounds is very simple we have already we have already studied it that when these ionic compounds are formed what happens there develops a strong electrostatic force of attraction between these ions right yes and this thing okay because of this strong electrostatic force of attraction what is happening when we are trying to convert the state okay of a particular ionic compound like suppose I have taken anycl okay so if it is in solid state so the particles are like very much closely held to each other right in this way okay but now when I have to convert it from solid state to liquid state we know that we have studied matter right and we know that in liquid state the particular substance the constant particles of that particular compound or particular substance are like slightly away from each other okay as compared to the solid state in solid state they are very closely held to each other so here when the consequent particles okay now here the constant particles are we have studied it ions right n a plus ions CL minus ions now they have to be separated so what what we have to do to separate these particles to make this particles move away from each other we have to weaken the force of attraction right the strong electricity force of attraction which is there between the ions we have to weaken it and for weakening this force of attraction what we have to do we have to supply energy right we have to heat it so when we are heating now it depends upon the force of attraction how much energy would be required now here the force of attraction is very strong it is it is strong electrostatic force of attraction it is very strong so high energy a large amount of energy is required okay now what does this mean we have to heat it till higher temperatures Okay and like in in ACL in the case of initial we have to heat it till 800 degree Centigrade then what happens our solid any cell gets converted into liquid anything and the temperature we know the temperature at which this any cell gates are not converted from solid to liquid state that temperature is the melting point of anything right now since it is very high temperature yes we got the answer why it is very high see the melting point is very much High okay because of the strong electrostatic force of attraction between the ions and in the same way when we are converting it from liquid initial to gaseous and acyl the particles now should be farther away from each other more further more far away from each other as compared to the liquid state right now we have to what we have to do again we have to again weaken the force of attraction from the liquid state whatever the force of attraction is there we have to again weaken it so again we have to give large amount of energy right which which means we have to heat it at higher temperatures and when the temperature is reaching this temperature one four six zero degree celsius roughly around 140 degrees Celsius then our liquid in ACL is getting converted into the gaseous inacial right so we know that this temperature okay at which the liquid and a cell will get converted into the gaseous and ecl is the boiling point of inacial Simply and yes this is very very high because of strong electrostatic force of attraction between ions so Friends next property is dissociation okay now actually you know the meaning of dissociation it means separation okay now in aqueous solution okay and in molten State okay of ionic compounds ions separate okay ions dissociate okay now what what does this mean or why is this happening let's see okay so in aqueous solution first let's understand what is aqueous solution aqueous solution means I have taken an ionic compound okay like initial and I have added it into the water okay so after adding the any cell in water what would happen aqueous solution will will be formed okay and molten State we already know if I convert the initial from solid state to liquid state so liquid state is called as molten State okay now in this small molten State and in this aqueous solution what is happening ions are dissociating ions are getting separated this means that n a plus and cl minus ions are getting separated okay now in this case both of both these cases now this means that they are now free to move okay you have to remember this thing if they are separated then they are free to move they are not now bonded to each other very strongly and why is this happening because the very reason I told you right now they are not bonded to each other very strongly right now the strong electrostatic force of attraction okay which was between the ions okay it has been weakened okay in molten and acquistade now since it is been weakened so the ions are like somewhat free to move okay the ions become mobile lines can move now why the strong electrostatic force of attraction is weakened see when we are converting from solid to liquid state just now we have seen that we are providing a large amount of energy right in order to weaken the electrostatic force of attraction strong electricity force of attraction so because of this supply of large amount of energy the strong electricity force of attraction beacons and ions get separated ions dissociate and in case of water or in case of aqueous solution what is happening water is also doing the actually same thing which the heat energy is doing okay water is also weakening the strong electrostatic force of attraction between these n a plus and cl minus n since the strong relative force of attraction is weakened so this n a plus and cl minus ions are dissociated they are separated and now they are free somewhat free mobile to move okay in solution and in the liquid state now let's connect this or let's relate this with electrolysis now don't worry about electrolysis we are going to study it in very much detail in a chapter okay it is a complete chapter but for right now let's just have a crisp idea okay how we can relate the dissociation with electrolysis so what what is happening see in electrolysis simply you just remember in this way there are two rods which are inserted okay in our aqueous or molten NAC okay so here there is aqueous or molten initial okay and in this aqueous molten inacial this two rods are dipped and these two rods are connected to a battery they are also connected to a bulb okay now what is happening I have switched on the battery so it is the positive terminal and current has been started okay current is has been started to flow from the positive terminal and it it has reached this Rod now when I start the battery I find that oh the bulb is glowing so this means that the current is Flowing from this positive terminal to the rod and then something is happening and the current is being conducted to this rod and again the current is being flowing through this wire and then the bulb is glowing so this means that something is happening here and there is a conduction of electricity and who is conducting this electricity this aqueous or molten in ACL is conducting the electricity now how it is conducting the year comes our dissociation so just now we saw that n a plus and cl minus ions are separated in aqueous and molten state right so this separated any plus and cl minus ions what they are what they are doing they are free to move right they are mobile so they migrate to the respective electrodes now here this Rod is called as an anode okay and this Rod is also called as an electrode this Rod is also called as an electrode and this is a cathode okay don't worry about the specifications or details so what is happening the positively charged species okay is moving towards the cathode okay and negative species is moving towards the anode so these ions are in short you remember right now is these ions are migrating towards the respective electrode and what is happening the electrical contact or electrical electrical contact is being established right and the electricity is being conducted from electricity is being conducted from by this aqueous or molten in Eco okay in this way we have related the dissociation with the electrolysis part so the next property is conductivity okay so first is heat so do ionic compounds conduct heat yes very well they are good conductors of heat but now moving to the case of electricity there is a Twist in the story okay these ionic compounds are good conductors of electricity when they are in the molten and aqueous state but they are poor conductors when they are in the solid state now why is this so just now we have related it right we just now have seen the electrolysis in which our acquisition molten State NaCl was conducting electricity right now we also know the reason why why it was conducting electricity okay so let's first start with why the solid state why the ionic compounds and solid state don't conduct electricity okay so strong electric force of attraction is present between the ions in solid state so the ions are not able to move right there are no free ions that now and if there are no free ions how they can migrate to the respective electrode they can't migrate so they can't conduct electricity now it's clear but now just now we saw that in acquisition molten State what is happening ions are dissociating ions are getting separated so ions are getting separated so they are like free to move they are mobile and that that is the very reason the ions migrate towards the respective electrodes and conduct electricity now why was this happening why the ions are free to move or why ions are dissociating in molten state or acquisite because the force of attraction between the ions is weak in molten and acquisite right so this also we have seen and why it has been weakened we know the reason very well okay in both the cases now the last property of any compound is solubility in water now I think I don't need to tell you this thing you already know because you would have definitely tried dissolving your normal common salt okay NaCl in water and you would have found that yes it is getting dissolved so yes ionic compounds are soluble in water now why is this so okay we are going to see it in very much detail when we would study water okay as I have told you before as well in covalent bonding okay but for right now what you can understand is water is a polar compound okay this also we are going to understand it in very much detail what are the polar compounds what are nonpolar compounds now since water is a polar compound what it is doing it is actually suppose I am taking this RNA compound initial so it is actually weakening the strong electrostatic force of attraction between these any presence here minus ions so what is what what would happen we have already seen this thing the ions dissociate right the ions get separated now they are free to move now they are Mobile in this aqueous solution and that's when we say that oh our salt has dissolved okay now it's time to see some questions so draw the electron dot diagram for the compounds given below represent the electrons by Dot and cross in the diagram they have given the atomic numbers of calcium oxygen chlorine sodium magnesium to us and now which compounds they have given for which compounds we have to turn the electron dot diagram first is calcium oxide now this was asked in your 2020 examination okay I have just summarized okay I have just pull up the questions for ease okay then second they have asked the electron reception of sodium chloride in 2019 in your icse examinations and third one is magnesium chloride they have asked this in 2017 okay in your examinations so all the three compounds electron or structure we have already studied right we have already learned I have told you how to draw the structures and this is the favorite question I guess of the examiners because these questions are like the electron dot structures they frequently ask in the examinations okay of different ionic compound as well as covalent compounds so what you have to do is you have to be thorough with this and how you would be thorough they know that if you know how to draw or if you can correctly draw the electron dot structure you know the process of formation of that compound okay so that's why I have told you to just remember or just understand how the ionic compounds are formed and then you would be easily able to draw the electron structure without making any mistake okay next is give a reason ionic compounds have a high melting point okay so this was actually your examination 2018. we have already seen the reason as well okay we know that they have high melting points and the reason as well right because of the strong electrostatic force of attraction between the ions okay so this is the keyword if you would miss any of the word then your marks would be and yes so why why we have to write the Y give a reason they have said okay so it is one mark question so we have to write the Y in very concise way we don't have to explain it in the whole manner okay so in concise way we can just write it in a one statement that because they are having strong electrostatic force of attraction between the ions due to which what we have to do is we have to supply large amount of energy to weaken this force of attraction okay so since we are now now it's understood that since large amount of energy is supplied so the compound is heated at high temperature and therefore it is having high melting point okay now next is fill up the blanks with the correct Choice given in the brackets ionic or electrovalent compounds do not conduct electricity in their Dash State okay so they have given us the two states fused and solid okay so fused here means molten state or liquid state okay so we have studied this that in solid state they don't conduct electricity okay they are asking us the ionic compounds do not conduct electricity okay in there which state so we know in few state or in molten State and in aqua State they conduct electricity but in solid state they don't conduct electricity and why we have already seen it okay so the answer here is solid state they do not conduct electricity in the solid state okay then State the type of bonding in the following molecule calcium oxide so this is asked in 2017. the previous was what previous question was asked in 2018 okay in your examinations so this kind of simple questions also are asked okay so State the type of bonding in the following molecule calcium oxide we already know we have studied it's all the ramayan Mahabharata so calcium oxide is having ionic bonding right so friends with this we have reached the end of this video and we have completed we have learned all the concepts of ionic bonding in this video so I hope you would have enjoyed learning with me you would have understood all the concepts but please do let me know in the comment section whether you have enjoyed or you have understood all the concepts or not and as you all know Matlab free helper best hair so stay tuned we will see you we will see the remaining concepts of this chapter in the next video till then bye bye and have a great day