[Music] when it comes to metals they behave very different from most other elements metals have some very peculiar properties they most of them seem to have high melting point apart from the exception of group one but even with group one they are excellent conductors they conduct electricity and heat very effectively with very little loss again except for group one they have high density they're very strong which can be interpreted as high tensile strength all of these properties tell us something must be similar in the structure of all metals as far as their structure is concerned you can also make wires from them a property that we call ductility so we say they are ductile you can make shields from them which we call malleability so they are malleable and all of these properties are pretty common in all metals some of them more in character in some metals and some and less but regardless metals behave like this now the explanation or the reason why all of this happens lies in metallic bonding the idea of metallic bonding says that metals are basically formed by not just atoms but these atoms lose the loss electrons the last valence electrons that they have they try to lose them and that's what metals do we know that's metallic characters whenever metals react they lose those large electrons so when they do that on their own they just lose them nothing to gain those electrons but they've just lost them that converts those atoms into cations so you have layers and layers of these atoms and these atoms lose these last electrons the valence electrons so the electrons are randomly arranged in there so there's no fixed pattern to where the electrons are and they're randomly arranged but that means these will be cations all of them are now positive ions and what happens is that all of these positive ions are pulling strongly on all the negative electrons and these electrons are so numerous that we say that we have c of b localized again that's a term that shows that electrons are no longer local to their own atom they are moving around c of d localized electrons and there's layers of cations and they have attraction to each other and this force of attraction is called metallic bonding so if somebody were to ask you what metallic bond is it's basically the force of attraction between c of d localized electrons which are mobile electrons they're moving around and they're negative and the layers of cations which are positive so positive attracts negative that's a fact so you have lots of positive ions lots of free electrons which are negative so they constantly attract each other then that strong attraction is called metallic bonding now the answer to why metals have these properties lies in this diagram you can see that the strong forces are there what that means is that because of these strong forces you will need to supply a large amount of energy to break down so why do they have high melting point because strong forces need or can be broken by large amount of energy so you need large amount of energy to break them similarly there is strong force which pulls these together and that's why they have high density that's why they have they're strong why are they good conductors the answer to why they're good conductors lies that they have c of electrons they have electrons that are moving around all the time which means they can carry those energy the electrical energy and move around and lastly the answer to why they are ductile and malleable lies into their layers these layers can slide over each other which means you can take some layers out for example i could take this one layer out and that is a wire that i have made so that ductile i could take this whole layer out and that is malleability i can hammer them into sheets and these cations slide over each other when we hammer them and that is the idea of metallic bonding [Music] you