 Hello everyone, we are just looking at the, yeah, we're just getting ready for the channel, okay? And excellent, I think everyone is out there. So you have the link, just feel free to post your queries on this link and I welcome you all just to really see if everything is working fine. I think things are okay and I can see that, yeah. So anyone who's joining the link, please put in your comments inside the chat window. I would also like to look at who all would be, who all are here already. Yeah, so let me quickly see if everything is all okay. Okay, yeah, and we begin, yeah. Right, so I welcome you all to today's session, which is on metals and non-metals. We will be looking at the entire, yeah, so there it is. Let me just put it on screen, perfect. I think it's good now. We are ready for the session. All those who are joining in, you can just put in your names in the live chat so that I understand who all are on the session. If you have any queries, you are most welcome to put in the queries in the chat window or just post it on WhatsApp. Personally, I should be able to answer them either during the session or after the session. I once again, I welcome you all to this crash course session where we'll be looking at metals and non-metals today. And all the different properties. We'll also try and see how to really write the answers for metals and non-metals. This is one of the very easy chapters in that sense, but at the same time, small details are important. What I would also like to say at the same breath is, while we are studying metals and non-metals, it's tiny integrities, tiny details and information is going to be pretty vital when we write these answers. So let's begin and understand what metals and non-metals really are. I expect the session to be lasting for about an hour, hour and a half and post which we can actually take up queries depending on everyone who is there. So yeah, so with this, I'm gonna take another minute to really see if everyone has joined in. Okay. And okay. So yeah, I think people are here already. Good. So it's nice to connect. Excellent. So let's begin with today's session. Let's try and see if we are really able to absorb the topic in its best possibility. Yeah. So yeah, feel free to post your messages and I'm here for you. Let's begin. So you see, we had seen periodic table and its properties in the previous session where we saw periodic tables basically is distributed into multiple types of elements. I mean, we categorize elements in multiple types. Some of them are metals, alkali metals, alkaline earth metals, transition metals, poor metals, rare metals, all of those. But if you really see on this table, everything that is beyond this line, so you can actually look at the steps that we have. So everything on this side of the table, so I'm just gonna make a huge circular mark. So everything on this side of the table is basically your metals and everything on the other side is non-metals. So you'll find that non-metals are really, really less in number and metals are really, really large in number. So this is the way that nature has configured different elements per se. But having said that, we'll also try and see why this is so and what are the different properties that actually make this differentiation happen? So let's look at the occurrence of metals and non-metals. So all of the naturally occurring the stable elements that we really have. So we have almost 118 elements now if you really look at the periodic table. 110 are shown here, but there are eight more which can be synthetically manufactured, stabilized. But having said that 92 naturally occurring elements, we have 70 metals and only 22 non-metals. So that shows that how skewed the number of elements is towards the metallic side. Now, in fact, there are some elements which show both the properties of metals and non-metals. They are called as metalloids. So basically you'd find that these are the elements which actually would also have, I'm just gonna put, yeah, and yeah. So these are the elements which also have the properties of both metals and non-metals. So you'll realize that, yeah. You'll realize that only some metals like gold and silver, they are actually found in the free state. Now, what do we mean by free state is basically they are found as metals, okay? So this is the entire lot, and they can be found in free state because they are very less reactive. And we'll see going further that why are they so less reactive and why are they so stable? Now, having said that, most metals are generally found in the combined states of oxide, sulfides, carbonates or silicates. So for example, you will find magnesium as magnesium oxide. You will find magnesium sulfide present. You'll also find magnesium carbonate, which is MgCO3. So most of them are generally found as carbonates or sulfides or oxides, even silicates to a large extent. But they wouldn't be very naturally available as metals themselves. Only gold, silver, platinum, palladium, these are few metals which are naturally available. But now some of the non-metals are actually found in the free state. The non-metals there are many which are found in the free state, especially the noble gas elements, which we also kind of term under the non-metal because most of their properties, like being issues, et cetera, are under the non-metallic character. So they are found in free state and some are found in either combined states like phosphorus, sulfur, in fact, we also find an S8 phosphorus, we find a P4. So they are generally found in the free or combined states, both. So this is a pure form of sulfur, but it is still, you can even find it in a multi-automic form, right? So the atomicity is more than one basically, right? So that's how non-metals also are looked at. Now let's try and understand what is the, how can we really differentiate between metals and non-metals? So if you really look at the properties of metals and non-metals, you will find that the most important properties that we have of metals and non-metals, especially in the physical properties, you'll find that I have listed out about eight of them taken directly from the NCRT for class 10th. And these properties are the physical state of the atom, they're melting in boiling points. We also have their density, millibility, inductility. So all of these are the properties of metals, which actually, we can really very clearly distinguish from other elements. So let's see what these properties really look like in both of these elements. If you look at the physical state, metals are all solid, except for two, which is mercury and gallium. In fact, gallium also is pretty much solid at room temperature, so around 25 degrees Celsius or less than that, gallium is solid. But if you hold gallium in your hand, it melts easily. So gallium is just liquid above 25, 27 degrees Celsius, about 300 Kelvin. But apart from that, except for mercury, all the metals you'll find are solid at room temperature. Some of them are very, very exclusive, but still in their natural forms, at room temperature, they are solid in state. But if you look at the contrast of non-metals, non-metals you'll find that most of them are actually gaseous. And except for a few, for example, bromine is liquid and iodine is actually solid. So iodine crystals are solid in nature. But apart from that, if you look at most of the other elements, non-metals, you'll find that they are all gaseous. Fluorine, nitrogen, oxygen, even for that matter, neon, argon, all of these are generally, you'll find that they are absolutely gaseous in nature. So that's the properties of non-metals. Now, if you look at the other properties of metals, let's look at the melting and boiling point in particular. So you'll find the melting and boiling points of metals, of course, they're being solids there. They have a very high melting point and of course, their boiling points also will be higher because the moment your melting point goes high, your boiling point has to, you know, equally rise. Except for, of course, we know a gallium and cesium. So cesium also has a very low melting point. But of course, non-metals, when they are in the gaseous form at room temperature itself, you'll recognize that non-metals definitely have low melting and boiling points. So this is a very important characteristic. But some non-metals which are covalently very strongly bonded like graphite and diamond. So diamond, in fact, the boiling point is very, very high, higher than a few of the metals. So you'll find that in such situations, that these are the only non-metals you'll find that they have a very high melting and boiling point. Most of the others will have a low boiling point. Let's look at density, right? So in density, we'll have, you know, generally they have a high density. So we have used the word generally because as a common denominator, you'll find that density of metals is mostly higher on the higher side. Whereas density of non-metals are lower side. Of course, they being gaseous, you can imagine that the density definitely is going to be a bit low. So that's density now on millibility and ductility because metals are like solids and they have atoms very closely placed to each other. You'll find that sheets of these atoms can slide over one another and you can find that they can be stretched or beaten up into sheets or even beaten up into wire or drawn into wires. So that's millibility and ductility for metals and of course they are. Now someone who is not solid in the first place, how can they be millable and ductile? And therefore, non-metals are neither millable and ductile and we don't even talk about these two properties for non-metals. If you look at the electrical and thermal conductivity, you'll find that metals are very good conductors. And one of the major reasons for metals being very good conductors are because they actually tend to give out the electrons pretty easily. And someone who has electrons or who can easily donate electrons, you'll find that their conductivity is pretty high. Now please note, when we speak about conductivities, there are two types of conductivities. One is of course electrical and thermal and they have different properties or factors that decide their high or low on conductivity. For example, if you look at the electrical conductivity, this is because of the presence of the electrons. Whereas if you look at the thermal conductivity, this is because of the rigidity. How rigid or how closely connected the atoms are. If the atoms are very closely connected, the thermal conductivity is going to be very high. And if you have more electrons that can be given out, the electrical conductivity is high. So the factors of electrical and thermal conductivities are dependent on different factors. Having said that, coincidentally for metals, both electrical and thermal conductivity are good. Whereas if for non-metals, of course they don't have any spare electrons. In fact, non-metals are all of those elements which take in the electrons. So their conductivities is low and they do not conduct any electricity or even further matter being gaseous. Their thermal conductivity also is pretty low. Now one important point is, for graphite, the only non-metal, where you can find that the conductivity is high because graphite forms a very unique structure of hexabons which can actually be extracted as sheets. And because every carbon is connected to only three other carbons, you'll find that it has a spare electron that is available on each of these carbons. And these spare electrons are basically responsible for conduction of electricity within the graphite molecule. So graphite is a very good conductor of electricity as well as a very good conductor of temperature also because of the rigidity of the structure it has. In fact, thermal conductivity is also very high for diamond because of the very strong bonding that it has between all the carbons. This strong bonding actually helps to have a very firm rigidity. And therefore if one molecule vibrates, which is the cause of conduction, you'll find that the entire structure starts vibrating and you'll find that diamonds are excellent conductors of temperature, but very poor conductors of electricity because of course in diamond, we don't have any spare electrons, but we have a very good availability of rigidity and therefore temperature conduction is very high. Now, lusher basically means shininess. So how much is an element shiny? And when we speak about shiny, it's basically a reflection of light that falls on these elements. So if you really look at the lusher metals because they have electrons and because also they have the ability to absorb and reflect the waves of light, you'll find metals are mostly very shiny. They are excellent reflectors, except for example, and non-metals. If you really look at non-metals, they do not have any of these properties. They do not reflect light waves and therefore they are absolutely non-lusterous except for iodine in non-metals. Iodine is the only one which is slightly shiny, although iodine has a blackish bluish color. You will find that it's somewhat shiny and can be comparable to all the metals. So that is how you will find that lusher is one of the interesting properties of metals and non-metals and which can be distinguished based on this. The next very important property is sonority or what we call a sonor sound. This is the sound that can be, we typically hear when we beat up a metallic vessel or just kind of make two metals dash against each other or create some sound. So that sound that the typical sharp pitch sound is what we call a sonor sound. Now, reverberating echo like sound. Now you'll find that metals, almost all the metals give this sonorous sound when they're struck with another hard substance. But of course, you know, non-metals do not have any sonorous sound. And of course, in the first place they are mostly gaseous, even liquid. So where would sonority come in, right? Unless you're really solid and very well rigid and structured, sonority is not something that we can even think about. And of course, you know, the final one is if you really look at the hardness, you'll find that metals are pretty hard. You know, they're generally hard in nature except for sodium and potassium and also for that matter, cesium, which are very soft in nature. But if you really look at calcium, you know, which is a major component of our bones and teeths, metals are very, very hard in nature. Non-metals on the other side, as we have been saying time and again, basic property being gaseous and all, they are very, very weak. In fact, they are absolutely soft in nature. For example, even iodine, iodine can be crushed with the hand, crushed with the hand. But if you really look at only, for example, graphite and diamond have been exceptions all across. In this softness, in fact, graphite also is very soft. It is only diamond, which is an exception. All the others are, you know, good in terms of their hardness. Now, these are the physical properties of metals and non-metals. Let's look at some of the chemical properties of metals and non-metals. So we basically will be looking at six different reactions of metals and non-metals. And, you know, how we have tried to categorize this is based on its property, you know, whether it is a reaction with a particular element or reaction with the counterpart, the metal with non-metal and non-metal with metal. And we have tried to put in some examples here, you know, taken up from NCRT at the same time. We've also tried to mention what really is the typical product when we look at such scenarios. So if you look at metals and non-metals, and the first reaction that we really have is, you know, reaction with oxygen. You'll find that all metals react with oxygen to give out metal oxides, okay? Except for very inert metals, for example, you know, your silver, your gold. So they don't react directly, of course, you know, with in presence of strong catalyst or at a very high temperature. They also form oxides, naturally they won't. But having said this, you'll find that metals and oxygen generally end up forming metal oxides. Two examples that can be seen on the screen is when sodium reacts with oxygen, you end up getting sodium oxide, which is Na2O. Similarly, when aluminum reacts with oxides, you end up getting aluminum oxide. In fact, aluminum oxide is also responsible for corrosion in aluminum. And now all of these metals are basic in nature, okay? So metals, metal oxides, and metal hydroxides, all of them are absolutely basic in nature. So you'll find that, you know, sodium metal oxides, which is Na2O, if you simply put water in it, you'll realize that it ends up being NaOH. So Na2O plus water is NaOH, and NaOH we know is a very, very strong base. So the property of NaOH you can also say is derived somewhat from Na2O. And therefore, you know, you'll find, this is one of the examples of metal oxides being very basic in nature. Having said that, as you start entering the transition metals, the acidity of the metals increases and there comes a point where metals tend to become amphoteric. But there is no metal oxide, which is acidic in nature, you know? So all the metals, in fact, zinc and aluminum are the least basic and they tend to become amphoteric, but most of the metals you'll find are acidic in nature. Now, except for zinc and aluminum, other metal oxides, you know, as we have said, they are basic. If they're soluble in water, they're also called as alkalis. So especially the first group metals who are soluble in water are generally termed as alkalis. Now, the other metal oxides generally are insoluble in water, and you know, for example, if you really see, CUO or zinc oxide are mostly insoluble in water, A2O3 for that matter. But if you really see some metal alkalis which are soluble in water, they will end up forming NaOH and we will have a basic solution formed in water. If you look at non-metal oxides, you'll find that most of the non-metal oxides are acidic in nature, so completely opposite to the metals. In fact, non-metal, not only oxides, but non-metal hydroxides and non-metal themselves are also acidic in nature. And therefore, we always find something called as acid rains that are possible, right? And with these acid rains are because non-metal firstly are gaseous and therefore they populate the atmosphere of earth pretty much, and whenever there are oxides of such non-metal present, we end up getting acid rains. So non-metal oxides are acidic in nature and only some of the non-metal oxides which are basically H2O is, this is H2O. So H2O is actually a neutral oxide. They are neither acidic nor basic. Again, CO, which is carbon monoxide, is again a neutral oxide, which is neither acidic nor basic. Most of the non-metal oxides are soluble in water, very opposite to the metal oxides. Metal oxides are insoluble in water and non-metal oxides are soluble in water and they dissolve in water to form their respective acids. So for example, when SO2 is dissolved in water, you will find H2SO3. When SO3 is dissolved in water, you will end up getting H2SO4. Let me give you some examples. So you can find that H2O plus SO3 actually ends up giving you H2SO4, okay? In the same way, if you really find CO2, which is the carbon dioxide when it dissolves in water, which is our aerated drinks, you end up getting H2CO3, okay? So which is called as carbonic acid. So most of the oxides of non-metal when they dissolve in water, they end up giving their respective acids. Now let's look at the second reaction with water. So most metals react with water to form metal oxides or metal hydroxides. And they would end up giving out the H2 gas. So a typical way to really see this, we had seen this in the last class as well in acid-base reactions. The detection of H2 gas can be done by taking a splinter or a small fire near the test tube where the gas is being released and you will hear a very pop sound. The pop sound is because of the small, explosive combustion of hydrogen to form water again. So any metal, generally when it reacts with water, it ends up giving out its respective hydroxide and hydrogen gas is released with a lot of heat. So this is a typical reaction with water. Now the other reactions of non-metals, they generally firstly do not react with water at all. Most of the non-metals would actually only react with steam and even non-metals react with steam to give hydrogen gas themselves because non-metals cannot give electrons to hydrogen in water. So it cannot release hydrogen gas in H2 gas in water. But the same non-metals actually end up releasing hydrogen gas in steam because at steam, you have very high temperatures and you will find that the hydrogen gas is released back. So here's the reactions for metals and non-metals for water. Now let's look at the other properties for metals and yeah, so now that we have seen reaction with water, we'll look at the properties of, chemical properties of metals and non-metals with respect to other substances for reaction. For example, with dilute acids. So all metals with dilute acids again end up giving up hydrogen. This is typical to metals giving the same pop sound test when with sprinters, so HCl with MG will give out MgCl2 and hydrogen gas, whereas H2SO4 with NA will end up giving Na2SO4 and hydrogen gas. So you'll find that metals actually end up giving this hydrogen gas except in one situation where hydrogen gas is not displaced from HNO3. So metal does not react to the HNO3 because HNO3 itself is a very strong oxidizing agent. So if MG actually reacts with HCl, you'll find that MG is the oxidizing agent because it oxidizes HCl to give chlorine H2 hydrogen is taken out of HCl and MGCl to solve this problem. But when it reacts with HNO3, hydrogen is not really given out because hydrogen HNO3 is more stronger in oxidizing reagent than any of these metals. Now, if you look at non-metals, non-metals do not react with acids because they themselves are very acidic in nature as we just saw a few minutes ago. And of course, non-metals cannot lose electrons to give it to hydrogen ions, so therefore they do not displace hydrogen ions and hydrogen ion gas cannot be released as you can see in these other non-metals. But there is one exception for HNO3 in terms of manganese, which I have actually mentioned here. So manganese actually reacts with HNO3 to give manganese nitrate and hydrogen gas. So it is the only one which actually is able to displace HNO3. Okay, so that's a quick exception for non-metals. The next reaction is reaction with salt solutions. So if you really take a metal and you put in a salt solution, depending on its reactivity, the metal will end up doing displacement or double displacement reaction if there are two salts. If there is just a metal and a metal salt, you'll end up getting a displacement reaction. So for example, zinc put in C-U-S-O4, you end up getting zinc sulfate and copper, okay? So more reactive element will displace the less reactive element from the solution and help it precipitate out. Whereas in non-metals, if you put it in the salt solution, the same displacement happens between reactive non-metal and less reactive non-metal. So in our scenario, you can find that chlorine is a more reactive non-metal and NaCl is more soluble in water. So chlorine displaces bromine from NABR and BR2 is found. So you end up getting bromine in the aqueous solution. So this is reactions with salt solutions. Now let's look at the next reaction which is, yeah, so I've taken salt solutions here again and let's look at the reaction with chlorine. So if you really look at the, so chlorine we have taken up specially because NCIT does mention reactions with chlorine more specifically. So whenever a metal reacts with chlorine, you end up getting metal chloride. So metal chloride is actually an ionic bonded compound. So metal being very strongly electropositive bonds with chlorine, which is very strongly electronegative in the ionic form. And a normal salt is formed. This ionic compound is very soluble in water. And if it is a solid, then it forms a very rigid structure or what we also call as crystallitis. The same reaction if you take non-metal and chlorine, you'll find that the non-metal chloride is also formed, but with a covalent bond. So that is the difference. In metals, it is formed with an ionic bond. In non-metals, it is with a covalent bond. Now this covalent bond is, so if you really look at HCl, you'll find that HCl actually also dissolves in aqueous solution pretty easily. HCl is an ionic compound in this scenario, but I can, for example, we can look at CCl4. We also have compounds like in chlorine, you'll find that PCl5 is there, phosphorus pentachloride or phosphorus trichloride. All of these are non-metal chlorides and they're pretty much covalent. Most of them are gaseous in nature again, because non-metal themselves are gaseous and chlorine also is gaseous. So their product in the end ends up giving up a gaseous product. So that's reaction with chlorine. If you just look at reaction with pure hydrogen, which is some water reaction of opposite of metals reacting with water, but except that the oxygen is not present in these reactions. So if you simply take a metal and you react it with hydrogen, you'll find that a metal hydride is produced and hydrogen most of the times is less electropositive than the metal. You'll find that metal hydrides are formed in which hydrogen actually ends up taking the negative charge H minus and the metal takes up the positive charges. So a metal hydride is formed in non-metals. Whenever it reacts with hydrogen, it ends up forming the hydrides again, but it depends on who is more electronegative. For example, in H2O, oxygen is more electronegative and you'll find that O minus in H plus is formed. In H2S also it is sulfur who is more electronegative and S minus in H plus is formed. So these are also hydrides, but at the same time, the polarity is slightly different between metals and non-metals. So that's a very important difference when metals or non-metals react with hydrogen. So they form their respective hydrides. So we have seen six reactions. We have seen reaction with oxygen and reaction with hydrogen, just to remember. Then we have seen reaction with acids and reaction with salt solutions. And we have seen reaction with chlorine per se. So yeah, salt solutions, acids, yeah. So we have seen all of these reactions, displacement and double displacement reactions now. Let's look at the metallurgy part of metals and non-metals. So you'll find that these are some very important terms in metallurgy. So let's look at what metallurgy is. So metallurgy is the science of extraction of metals from their ores. Let's understand a quick, in fact, we'll see in the very next slide, what is the difference between ores and their minerals? Now metallurgy in this slide, you'll find that it's the science how we extract metals because they are finally utilized for various uses, whether it is industrial or any other. And they also need to be purified from their ores. So there has to be processes, industrial or lab, whichever is it, so that we actually are able to extract pure forms of metals from their compounds. Now, what are minerals? Minerals are all of these naturally occurring substances where you have one or more elements in there or their compounds. So you can find metal compounds in minerals, but all minerals cannot be utilized for industrial processes or lab processes. Now, you'll find that only a few minerals can be utilized for really profitably extracting minerals out of them because of the processes that we use. So there is an economic benefit that is availed whenever we have metals extracted out of minerals. And in whatever minerals we are able to extract metals, those are called as ores. So if this is the space of minerals, then ores is a small space of it. And this is the one that we only use industrially or through lab processes to extract elements or metals out of them. What are the different types of metallurgical processes to extract this metal from its ore? Generally, there are three types of processes. First is the concentration of ore. Second is the reduction of ore. And the third is refining of the ore. We will quickly look at what these three processes really mean and how can we really do that? In concentration of ore, we remove the impurities from the ore. So essentially we try and really try and bring down the impurities or unavoidable substances from the ore. For example, a few of these impurities could be simple sand, soil, unwanted particles inside the ore. So what are the different ways of concentration? There are multiple ways. We are going to talk about a few physical methods. For example, one is using magnetic separation. Magnetic separation is used for ores which has magnetic properties. So if a particular ore can be attracted by magnets, then the metallic part will get attracted and all the other parts can be actually thrown out. The second one is the gravitational separation. So in gravitational separation, the gravitational attraction force is what is used to distinguish between metals and its impurity. The third one is separation through a running water. So anything that actually wets the impurities can be taken out through simply washing. And that's the easiest way that you can actually make something get out of the way. So that's running water. There are some other methods where you actually use leaching. For example, in aluminum, you use a process of leaching where aluminum is concentrated to form sodium aluminase. So that's another way that you can actually do that. One more method is very simple, is crushing the ore. So you simply crush the ore and you see it. So see through a filter or through a mesh and you will end up getting very good concentration of metallic particles. So these are a few methods of concentration of the ore. Now, after the ore is concentrated, we undergo a process called as reduction. So the ore is then reduced and a pure compound is, a metallic compound is obtained. So after concentration, in fact, most of these reduction mechanisms are done on oxides of metals. So you end up getting a metal oxide as the byproduct of the entire concentration and extraction process. And then reduction is applied onto it to end up giving a pure metallic form. Now, and once a metallic form is formed, this metallic form can further be purified into metals to obtain pure metals. So even this form, there might be some impurities that can exist. So just to get a very pure form of the metal, refining processes are taken up. We are going to look at the reduction and refining process in slightly more detail in the upcoming slides. Yeah, and yeah, so let's look at how we really undergo the refining part. Yeah, so we just saw the occurrence of metals. So in earth crust, you'll find that metals are present as minerals or ores and we just saw this difference a few minutes ago. Elements and compounds, which are of course naturally occurring in the earth's crust are minerals, but from minerals where we have a high percentage of particular material that can be taken out, and metals can be extracted economically on a large scale, that's what our ores. So you can find that aluminum can be extracted from bauxite ore, as well as iron can be extracted from hematite ore, and these are very profitable ores, which can be used for industrial purposes. Now, let's look at the extraction of metals in the classical form. So you'll find that metals firstly once it's concentrated and its enrichment is done, you'll realize that most of these metals are with impurities, which is also called as Gange. Now, the separation of these metals from its Gange actually depends on the physical and chemical properties of the ore and the Gange itself. So some of the most important factor that is utilized or kept in mind, why do you actually decide on what property should we really use to differentiate or extract the metal, you'll find that the reactivity comes very handy. So metals which are very, very reactive, sorry, yeah. Metals which are very reactive, you'll find that most of them we tend to extract them through a process called as electrolysis. So electrolysis is nothing but simply using raw electricity and providing a flush of electrons to the metals so that they precipitate out in the electrolytic cell. So metals which are highly reactive like sodium, potassium, magnesium and aluminum, the electrolysis of their molten ore is done and pure metal is tried to be extracted or it's tried to extract pure metal from their metal ores. Whereas in medium reactivity, these metals mostly are formed. So high reactivity metals are formed in their salts. They are also formed in terms of their oxide, sulfides, carbonates, all of them. So generally these metals are brought down to their molten state and simply electrolyzed. But if you look at medium reactivity, most of these metals are generally formed in two forms. One is the carbonate form and the second is the sulfide form. Now if you really look at the carbonate form, if you heat the carbonate of any metal, let's say for example zinc carbonate, CO2 is released and we end up getting zinc oxide. So even if we do not supply and particularly we do not supply and we keep absence of air because the other impurities do not get oxidized. Whenever carbonate is heated in the absence of air, this process is what we call as calcination. We are going to look at the difference between calcination and roasting in just a few minutes from now. And whenever we heat the same ore, especially the sulfide ores in the presence of air, it is called as roasting. So using these two processes and on the ores of, for example zinc, iron and lead, which are medium reactivity elements, we end up getting oxides of these metals. So you'll realize that all of these metals generally end up at oxide stage and which is further reduced. So this is the reduction phase of the oxides where we reduce these oxides using carbon and we end up getting pure metals. So this is the method for medium reactivity. So as I had mentioned earlier, just a quick recap. Metals are distributed into high reactivity, medium reactivity and low reactivity. And someone who is medium reactivity goes through a process of either calcination, roasting and oxides are formed, which further is reduced to metal using carbon. Now substances which are really low reactivity, like copper and silver, they end up, so for them, since they are very low in reactivity, they're self, again, we primarily use sulfur and sulfide ores to end up giving metal oxides. So sulfides burn to give out C-U-O or A-G-O and they can further be reduced by carbon. So, and you end up getting pure metal. The main difference between medium reactivity and low reactivity is in medium reactivity, most of the metals are undergoing both the processes as an individually, but you might use calcination or roasting either of them and then further go to reduction, but in low reactivity, if the metal is very, very low reactive, you don't even need to use any extraction process except for cleaning. For example, we end up getting gold nuggets which are in the pure form, the metal itself is found in the pure form. So least reactive are, you know, you can consider from copper to silver. In fact, what is seen on the screen is the reactivity series of metals. So it goes from potassium to gold and this reactivity series can also be memorized through different acronyms. One of the common acronyms that you'll find across the board in schools in Google also is that they call this as please stop calling me a cute zebra. So here there has to be a carbon. The carbon is another benchmark. So you can put a carbon above a zinc and you can say, please stop calling me a cute zebra. I like her call me smart goat. Okay, so this is a quick acronym that can be used by all so that, you know, we understand and remember the reactivity series of the metals. The reactivity series is very helpful to distinguish between reactive and non-reactive elements. Generally up to aluminum, we consider them as most reactive from aluminum to hydrogen. So hydrogen is a non-metal, please mind it. So hydrogen is another benchmark where we keep it distinguished. So in fact here, you know, carbon is maintained as, you know, to distinguish the reactivity series between most reactive and moderately reactive and below hydrogen are all least reactive. So this is the reactivity series which decides who is more reactive and who is less reactive and who will displace the other. Let's say there is a reaction that happens in them. Now, as discussed, you know, let's look at the differences between calcination and roasting. So in calcination and roasting, calcination is mostly done for carbonate ores. And we saw that, you know, it is in the absence of oxygen because if carbonate ores are simply heated enough, they will end up giving out CO2 in the atmosphere. And you'll find that the metal oxide is left behind in the reaction mixture. Now, this process is mostly used for carbonate ores as we have seen. And, you know, these carbonate ores are generally found in the medium reactive metallic zone. So anywhere between zinc and, you know, if you really look at the previous slide between zinc and lead, okay, zinc and iron lead. So all those are the medium reactive elements. Now, if you look at roasting, roasting is done mostly for the sulphide ores. So it is actually done in the presence of oxygen. So you will see that SO2 gas is released because the sulphur actually gets oxidized to form SO2. At the same time, zinc also gets oxidized to zinc oxide. Again, zinc, iron lead are the compounds where roasting can be used. In fact, roasting can further be used for low reactive elements also till the time that elements themselves are present in their normal form because they are non-reactive. They can be present in their normal form. How do we really have refining of the metals? So once the metal is produced in the oxide form and it is reduced further, so that the process is called as smelting. And what happens in smelting is we put all of these oxides into, with carbon. So let's say you have a metal oxide. So with carbon or coke, you simply end up getting some more of CO2 which is then filtered before releasing in the atmosphere. Most of the times, carbon sequestration or some non-polluting reagent is used. And you end up getting, once CO2 is formed, the other metal is given out. So the only process for all of these at the end of formation of metal oxide is to actually convert it into a metal and CO2 through smelting with pure carbon or coke. Now, after metal is formed, this is still again not at most purity. Of course, the 90% of the solution or reaction mixture now left is metals. But having said that, if you have to purify it to 99.9% grade, then most metals are generally purified through electrolytic refining, where metals are deposited at the cathode. So cathode gives the electrons to the metals and metals stick on or deposit on the cathode. Whereas, the anode is used of the impure metal which generally would take away all the impurities with itself. And then anode more that will be formed. So these are metals and non-metal purification processes, especially calcination and roasting. Now, let's look at some important compounds of metals and non-metals, especially the compounds that are formed between them, between for example, a metal and a non-metal. So you will find that whenever a metal forms a compound with a non-metal, metal being highly electro positive will form an M plus, which is a positive cation. And non-metal being highly electronegative will form an NM minus, which is an anion. Anion is the ion with a negative charge and cation is anion with a positive charge. You'll find that the physical nature of this compounds will be very strong and hard because of the amazing ability of their charges to attract each other. The force of attraction is pretty strong and they would also generally be brittle in nature. So why brittle is because it's very easy for them to be broken into pieces. And therefore, we'll find that these are ionic compounds that can be really looked at, okay? So that's one important aspect. Then the melting and boiling point of all of these ionic compounds is also very high because it needs a large amount of heat energy to break the strong ionic attraction. And therefore, the melting and boiling points are generally very large. If you look at the solubility of ionic compounds, they are very highly soluble in polar solvents. So in polar solvents, you'll find that it dissolves pretty easily and in insoluble solvents, they will be insoluble in kerosene and petrol, which are basically non-polar. And the reason for this is, of course, like dissolves like and therefore, there is a, yeah, like dissolves like and therefore, you'll find that polar substances get dissolved inside polar solvents. So there's a question by Brian who says, sir, is melting and reducing using carbon done to serve the purpose of getting the metal out of its oxide state? If so, what is the difference between the two? Smelting is the process through which we take metal out of its metal oxides. Reduction is a general term for it. Most of the processes, as we see and study metallurgy in much more detail, you'll find that reduction can also be done by some other processes, for example, passing hydrogen gas, et cetera, especially in the lab methods, not the industrial methods. But yes, smelting is the process of getting metal from its metal oxides and there is no specific difference between the two in the processes that we study in our syllabus, but at a larger scope, reduction is for any substance giving out oxygen or getting bonded with hydrogen or simply increasing in its oxidation state, decreasing in its oxidation state. That's reduction, but in general, reduction is utilized to take out oxygen and get pure metals, whereas smelting is just one specific process where carbon is utilized. So that's smelting. So this is the difference between the two. Yeah, so that's a quick answer to the question by Brian. And let's look at the further properties of ionic compounds. You'll find that solubility of ionic compounds is very high in polar substances like water. In fact, even in ethanol or ethyl alcohol, the solubility is high, but it is very low in substances like kerosene and petrol. On the other side, if you look at conduction of electricity, ionic compounds do not conduct electricity in the solid state, but they conduct electricity in molten or aqueous state. That is very important in molten or aqueous state. They do conduct electricity very easily. So that's the property of ionic compounds, especially because ionic compounds have a lot of free electrons in the molten or aqueous state and therefore, or rather, the electron mobility is quite high and therefore, they can conduct electricity in the molten or aqueous state. Now, yeah, so I've just mentioned the reasons for that as well, that ions cannot move due to the rigid solid structure. So ionic compounds conduct electricity in molten state and ions can move freely in the electrolysis, since the electrolysis static forces of attraction between the oppositely charged ions are overcome due to heat in the molten state. So these are some statements that you have to be very particular when you write answers to these questions and the properties of the ionic compounds. Now, let's look at non-metals or, sorry, noble metals. So noble metals are like noble gases. In noble gases, you will find that most of these substances are very non-reactive. In most of these substances, you will find that they are very stable at the room temperature or in natural conditions. Few examples are gold and silver. So you will find, second, sorry, yeah. So you'll find that they also do not react very easily with dilute acids or with air or even with water. So all of these are basically those substances which can retain their luster and can be very well used in multiple processes without getting affected at all. So like noble gases, they are noble metals. But please note, noble gases are inert to a very strong extent. Noble metals are not strong enough to be inert for a very long time. For example, if you use strong acids or if you use high temperatures, you'll find that noble metals also react. For example, gold does form AUO or silver does from AGO. You'll find that platinum also does react, but at a very harsh conditions. So the point is noble metals are only inert within a certain boundary of conditions and at natural temperatures and natural conditions. Now, one of the major important reasons, reactions that noble metals have and which is concerned with our syllabus also is the reaction with aqua regia. So aqua regia is a mixture of concentrated nitric acid and HCl. And you'll find that gold actually dissolves in aqua regia forming gold oxide. So gold gets oxidized inside aqua regia forming gold oxide. And this is one of the very strong oxidizing agents. So aqua regia, which is actually the mixture of nitric acid and HCl. So you'll find that nitric acid HNO3 in itself is a strong oxidizing agent. But having said that, when it couples up with HCl, its oxidizing ability increases manifold times. And therefore this mixture of one is to three is actually a very, very strong mixture to oxidize any inert metal as well, like the noble metals that we have seen and therefore it dissolves them. There's also another reaction that is used to purify gold. So for example, you dissolve gold and then you precipitate it out again. So at a very molecular level, you are able to make gold pure. The next one, yeah. So that's what we have mentioned here is that pure 24 caramel gold, which is very soft and cannot be, it actually cannot be used for making our elements. So a small amount of copper or silver also is added to it. This actually brings in its hardness and this is what we use for all practical reasons to really go forward with. So that's noble metals. Let's look at the uses of metals now. So where are metals used and what can we really understand about different metals that we study? So you'll find that, yeah. And we again have paramjeet, your high paramjeet. I hope you're able to connect. Yeah, so yeah. So we have uses of metals. So iron, which is the most common metal that we have, it's basically used to make pins, it's used to make nails, nuts, bolts, tools, machines. So a lot of uses. In fact, most of the construction, it happens on the basis of using this metal. And it's a very, very useful metal. The only problem with iron is that it rusts pretty easily. So so long that we are able to contain the rusting, iron is pretty useful. It also has a lot of strength. Now, the second metal that is very important for us is aluminum. Now you'll find that aluminum is used to also for multiple purposes, for example, making utensils, wires, furniture, parts of aircrafts and vehicles, machines, packing food and medicines. Now one of the major properties of aluminum is that it is quite malleable and it is also corrosion resistant. So whenever aluminum is exposed to air or moisture, you'll find that the upper layer of aluminum, so let's say this is an aluminum plate, we'll find, sorry, we'll find that the upper layer of aluminum actually gets corroded and it forms a small sheet above it. And this sheet further, yeah. So yeah, this sheet, one second. Yeah, so this sheet further, which is corroded, actually does not allow any more amount of air or water to penetrate and destroy the metal further. So aluminum in that sense is quite durable and it's also a very good conductor of electricity and heat, one of the major reasons that it is used for utensils also. So that's aluminum for us. And then we have copper. Copper is used for making wires an excellent conductor of electricity, of course, after silver, but silver being pretty costly. We end up using copper in wires for vessel bases because it conducts electricity and heat pretty ready. So that's one of the easy uses of copper. And then we have gold. So gold, of course, is used in jewelry making coins and making metals, one of the precious metals. So gold is something that we all have used and seen. And then we have silver. Silver is also used to make jewelry and coins. It is more readily available than gold and therefore it's slightly cheaper as compared to gold. There are, in fact, silver is also used in small amounts in making wires in very, very important applications. For example, computer applications where conduction of electricity is supreme. So yes, silver is pretty much used in all of those. And then there is platinum. Platinum is also a very rare metal, very niche metal, very much in demand. And therefore it also has a very high cost. So it definitely used in making jewelry, some electrical gadgets. Platinum is also a very good catalyst. So in most of the reactions with hydrogen or alkenes, you'll find that platinum is used. And then we have sodium. Sodium is used as common salt. It's used in chemicals. Sodium is a very, very reactive metal. Also it is something that we use on a daily basis in our food, but it's very difficult to find it in the metallic form. In fact, it is stored under kerosene because of its reactivity. So that's one important metal. And then we have calcium. Calcium is, its old dolomite is pretty much used instead of gypsum, which is CS4. We saw it in the last chapter in acids and bases. It's also used in making glass at times. So calcium is another very important element that we can really look and we study here in the syllabus. Now let's come to, yeah. So that's uses of metals. Let's look at the uses of non-metals. So you'll find that the non-metals are also almost in daily use. We interact with sulfuric acid through the air, the air that we actually smell. We have quite a percentage of sulfur in it. I think it's to the tune of 0.2, 0.3%. And there are also a lot of salts of metals that it makes. For example, you know, N2S sodium sulfide or calcium sulfide is pretty common used in the laboratory methods or laboratory preparations. Oxygen is one of the most common and most abundant non-metal. In fact, a lifeline of the entire living things. And it's definitely used in the respiration of living things, but it's also used in burning fuels. And that is how energy is produced. So all of these are very important non-metals for us. Nitrogen, which is actually the maximum portion or component of the air, almost 70% plus, you know, 72 odd percent, 72 odd percent is used in making ammonia. This is a very, very important chemical again. Ammonia is not only used in lab methods, but also used in making urea. It's also an important component of all the fertilizers that we use in NPK. So ammonia is one of those compounds which are used to produce a lot of organic elements, secondary elements. So that's nitrogen. And then we have hydrogen. So hydrogen definitely is used in making nitrogen, but it's also used in making fuels because it has a very high calorific value and it can be compressed very easily. And therefore a lot of energy can be stored in a very small space. So liquid nitrogen or cryogenic nitrogen is something that can be used. It can also be used in welding. So all of that is pretty much available for us. And then we have chlorine. Chlorine is used to kill germs. We have heard about chlorination of water and we have heard about chlorination of swimming pools. So all of this is pretty much available. So chlorine is used to, as a disinfectant, very much for cleanliness and making water pure, purified water. It's also used to bleach. Like we have seen in acids and bases again, bleach can be made from chlorine itself. And then we have iodine. Tincture iodine is used as an antiseptic. It's basically used to have to clean the wounds. Iodine is also used as food particles. It's one of the isotopes of iodine is very helpful in having relief from goiter, which is a disease. So iodine isotope is used in the treatment of goiter. So these are a few uses of non-metals. And I think most of them are important for us to be remembered. Now let's look at alloys. So in ninth grade, we had looked at mixtures. So alloys is actually a mixture of two or more metals. So we look at some important alloys. For example, steel is a very important alloy. It is a mixture of iron and carbon. And of course used in construction of tools, machines, tanks, ships, rails. So steel is a very, very strong compound and very variant in using them across the, across the preter of applications. You'll also find that an alloy is a very homogeneous mixture of one metal with the other or sometimes even non-metals are used. So these are done so as to retain the individual properties of different components. So that's why alloys are basically made so that the goodness of multiple elements can be brought in together. Now steel also has variant of stainless steel. So not only carbon, but chromium, sometimes also nickel and all are used. So iron and chromium, whenever they are put together, you end up getting stainless steel. Basically used for utensils, cutlery, surgical instruments, et cetera. And then you have brass. So brass is actually a mixture of copper and zinc. So brass is used again to make utensils, handicrafts, musical instruments. Brass is pretty durable. Also it's very good in terms of conducting electricity. It's also, it looks, you know, it has, as you know, most of the cultures have a tradition to maintain brass utensils. So pretty much useful across, you know, the daily use. And then we have bronze. So bronze is actually an alloy of copper and tin. And it's actually used to make metals and statues, belts and ornaments have been used in bronze ages. So it's a very old alloy dates back to even, you know, the era where, you know, we don't have written documents. So since then bronze has been in place. And then we have alnico, which is an iron, aluminum. So basically alnico comes from aluminum, nickel and cobalt. So, and some portion of iron also is used in it. So it's basically used to make magnets. They are very good magnets. They can be polarized and can be used in making magnets. And then we have duralium, which is, the alium comes from aluminum and this dural comes from its ability to have extreme pressure. So duralium is basically copper, magnesium, manganese and aluminum alloys. And they can be used in making utensils, pressure cookers and vehicles, air carts because of its durability, its ability to withstand high amount of pressures and temperatures. So that's alloys for us. Most important alloys that we really need to remember. And the last topic that we have for today is, in this presentation is corrosion. So you'll see that, yeah, so you'll see, corrosion is actually, yeah. So some of the metals get corroded when exposed to moist air. So for a long time and this property is called as corrosion. So the corrosion of metals can be prevented by applying oil and grease. So basically when we cut the contact between, the water, the vapor and the air, the oxygen, then metals do not get corroded. So when we apply oil or grease to metals, we can stop corrosion. So corrosion is the process of forming oxides, okay? So whether it is aluminum or whether it is iron, let me use a different color so that we actually can retain. Yeah, let me use black. So whether it is iron or whether it is aluminum or iron, when they end up getting reacted with oxygen or water, you end up forming their respective oxides, whether it is ALO3 or Fe2O3 or FeO. And these oxides are called as corroded metals. So you'll realize that the corrosion of metals is something that is not desirable because most of these metals would then get broken down into weaker substances, which is undesirable. So an undesirable change caused to metals is what corrosion is about. And you'll find that corrosion can be avoided either by applying grease or by applying paint. Sometimes galvanization is also utilized. So basically you coat metals with some non-corrosive metals like zinc and zinc is more reactive than any other metals. So therefore zinc sacrifices itself before letting, let's say, iron get oxidized or aluminum get oxidized. So coating of zinc is what we call as galvanization. And therefore a very unique question that is asked in most of the exams is, even if the zinc plate is broken or is discontinuous and water seeps in, still the metal does not get corroded why? And the reason for that is before the metal gets corroded, the zinc plate which is above the metal itself will get oxidized and will sacrifice itself instead of the metal and we will end up getting zinc oxide. So that's the problem that the zinc can, because of being very reactive, it faces itself. And therefore it can be a very good abider of corrosion for most of the metals. And then the last one is electroplating. Electroplating is basically coating of metals and with non-corrosive metals like chromium tin and passing of electricity. So basically what we do is we put up two metal rods which is anode and cathode. We are going to see more of this in the following chapters. But just a quick look at this is, the impure metal is used as anode and it dissolves into the solution in the electrolyte and the pure metals get deposited on the cathode. And as it gets deposited, the impurity remains in the solution in the vessel. And we will find that the metal gets pure. That's one refining way. But on the other side, as the metal gets deposited on something, it covers the complete metal and we can cover something with a non-corrosive element. For example, metals like chromium and tin are electroplated over metals like iron, which actually avoids corrosion. So that's one reason. And the last is making alloys. So iron is alloyed with chromium or nickel and it forms stainless steel, which in itself is also resistant to corrosion. So alloys retain the property of being non-corrosive and helps in avoiding corrosion. So these are the different mechanisms of this. So a quick look at this chapter. So we started with understanding what metals and non-metals are and how they occur in nature. We saw their physical properties, almost eight of them. We compared them to each other. And then we saw its chemical properties. We saw almost six, five reactions. One reaction is just repeated. So we saw five more reactions, including reaction with oxygen and hydrogen reaction with water and acids and the reaction with salt and chlorine. So yeah, water and acids, salt and chlorine and hydrogen and oxygen. So we've seen those six reactions. Then we had looked at metallurgy and we have seen one of the different aspects of metallurgy that we have to understand what are ores, minerals and what are metallurgical processes? What are they classified into? We have also seen reduction and refining. One of the important differentiations that we should know about is between minerals and ores. Then we've seen the processes between different metals and they are based on their reactivity. So whether it is low reactive, medium reactive or high reactive. And we also have understood the reactivity series. We had also seen the reactivity series in acids and bases. The high reactive element displaces the low reactive element from the solution and remains in the solution. And we have also seen how to distinguish between them. So carbon and hydrogen are two different elements which are not metals, but utilized in the reactivity series just for differentiating between reactive and moderately and least reactive, keeping up some partitions. Then we've also seen the most reactive actually can be undergone through an electrolytic process, whereas medium reactive undergo either calcination or roasting and unreactive are directly taken out or simply roasting is given to them. So these are different ones and once all the oxides, all the intent of all of them is to end up getting oxides. Once oxides are formed, then we reduce with carbon which is also called as smelting. And after the smelting process, we end up getting pure metals which are refined further to get 99.9% purity. We've also seen the difference between calcination and roasting and we at this point, we had also looked at what smelting is. Then we learned about a few compounds of metals and non-metals, especially the ionic compounds. So what are the properties and why are they important? So their physical nature, their melting and boiling points and their solubility is what we have looked at and their conduction of electricity also we understood. And then we saw what noble metals were. Noble metals are very similar to the noble elements. We saw that most of the noble metals are generally non-reactive, when we create something very reactive like aqua-regia, which is a mixture of concentrated nitric acid and HCl at one is to three, it enhances the oxidizing ability of nitric acid and we end up dissolving even the noble metals from the solution. And then we have pure gold, which is very soft and malleable. So just to make it harder, we end up adding silver or copper. Then we saw the uses of a few metals, most important metals we have seen in their uses, their examples and uses. And then we seen examples and uses of non-metals. The last that we saw was alloys, some of the most important alloys that we should know about what they are made up of and what are their uses. These are the three important properties of alloys that we should know about. And then we saw corrosion and how to avoid it. So we have seen some methods of avoiding corrosion as well, about five odd methods. So these are the most important bits on metals and non-metals. And I hope you could write and you've understood the topic pretty well. I would urge that you look at the entire video once again whenever you feel uncomfortable, you can go through it. And my suggestion is write the answers in metals and non-metals point-wise so that the right keywords are utilized. And once the keywords are utilized, you can actually score maximum more than your potential. So that's about it. I wish you all the best on this topic and I hope we could connect better. I also look forward to your queries. If you have any of them, please try and post it on the group or ping me directly and I'll be most happy. If you can also have any of these questions put out to me, I'll be happy to answer them. Thank you so much and I look forward to connecting to you soon on the other topics and let's hope to keep this crash course alive in terms of the vibrant nature and the value that it adds to everyone. Thank you so much and see you again. Take care, bye.