hello great Els today we are going to start looking at chemistry so this is a chemistry topic we're looking at Atomic combinations chemical bonding all of those things so this is an introduction to chemical bonding and we're going to also recap a little bit of great 10 stuff but I'm also going to be introducing the new grade 11 work so let's Jump Right In Atomic combinations falls under the section called matter and materials and we'll be focusing on chemical bonding and the intro to chemical bonding in this lesson but before we jump into that I just want to show you your atps so this is the document that the government gives to schools and teachers and this is what you need to know according to the Department of Education for your exams so they show you in quite a lot of detail exactly what you need to know they break it down for you so you can pause the screen you can take a screenshot of this you can write it in your book and you can use it as a checklist I also have a document on my website that has this written up nicely for you already as a checklist you can print it and stick it in your book but basically this is everything that you need to know and this is everything that we'll be covering in this playlist right now there are a lot of definitions that you need to know for the section and by now you should know that definitions in physical sciences in physics and chemistry is very very important you need to be able to Define certain terms and you need to be able to give the important keywords in order to get your marks usually definitions are worth two marks so make sure that you learn these These are the easy marks in your exams and we'll be going through each of these definitions as we go through the work remember this is an intro video so we'll be starting off with what is a chemical bond we'll speak a bit about Co valent bonds and veence electrons stuff like that but we will go through all of this in the videos in the playlist right so chemical bonds you should know from grade 10 already and you did chemical bonding in a little bit of detail in grade 10 you need to know that atom are held together in molecules and compounds by chemical bonds okay and ions are held together in crystals by chemical bonds now if you think back to grade 10 we actually did three types of chemical bonds see if you can remember what those types are I will mention them again very shortly but think about what they are I give you a lot of Clues over here but this is basically what chemical bonding is this is what chemical bonding does but before we get into a chemical bond I want to make sure that you understand the difference between a chemical bond which is also called an interatomic force or int molecular force and an inter molecular Force there's a big difference you need to understand that now if I had to ask you to label the yellow line that you see between the O and the H and this dotted blue line over here that you also see between a o and H would you be able to label those lines do you know the difference you need to know that that this yellow line over here this thing that's joining the oxygen atom and the hydrogen atom that over there is called a bond and in particular this is a calent bond but we'll get into that now but this is a bond another word for a bond is an inra molecular Force intra molecular force or an interatomic force a lot of words for one thing but it's important that you are familiar with all the different terms because you never know when your teacher could use what term or your textbook or your study guide or your exam so this is a bond it is a electrostatic force of attraction between two atoms it's inside the molecule which is why it's called intra molecular think of intra as meaning inside so intra molecular means inside the molecule and it's also called an interatomic Force the word inter think of it as meaning between now if you read that again you you can see that inter Atomic means between atoms interatomic interatomic force or an intra molecular force or a bond that's that one now if that's that what is this blue dotted line over here it's not a bond it's not a bond okay it's not an intra molecular Force it's not inside the molecule this is inside inside the molecule this is not inside the molecule it's not interatomic it's not between two atoms of one molecule what this blue dotted line is it is actually called an inter molecular force and that is a whole another topic that you'll be learning in grade 11 inter molecular forces it's a very important topic and it follows this topic that we're currently doing now remember inter what does that mean again that means between and molecular means molecules so this blue dotted line is between molecules and that makes sense because this blue dotted line is connecting water molecule number one with water molecule number two there is a difference between bonds and intermolecular forces don't get them confused so here's another diagram that maybe summarizes the differences here you can see the CO2 molecule and I've highlighted the bonds or the interatomic forces in green okay it's between atoms intermolecular forces are not Bonds another important thing that you need to know in this video is that we have three types of bonds these are three types of interatomic forces and I've listed them up there you did learn about them in grade 10 but they are Cove valent bonds ionic bonds and metallic bonds now what you need to remember and what you were taught last year about the three different types is that Cove valent bonds is between a non-metal and a non-metal okay non-metal atom non-metal atom so for example H2O hydrogen is a nonmetal oxygen is a nonmetal or carbon dioxide carbon is a non-metal oxygen is a non-metal and so on then we've got ionic bonding ionic bonding is a bond between a metal and a nonmetal so for example something like na sodium is a metal chloride chlorine is a non-metal the metallic bonding consists between or exists between um metal atoms within the same metal okay right now you need to know the proper definitions for coent Ionic and metallic bonding as well so coent bonding as I showed you earlier in the video the definition is over here coent bonding over here is the sharing of electrons between atoms to form molecules and what I would just add in there is is the sharing of electrons between two nonmetal atoms to form molecules it's very important to remember that coent bonding is when the two atoms share and ionic bonding which is actually not here behind me but ionic bonding involves the transfer of electron of an electron or electrons from the metal to the nonmetal atom and that is how the bond is formed so you need to know the proper definition if we ask you to Divi to Define coent bonding you can't just say coent bonding is between two non-metal atoms you need to tell me that coent bonding is the sharing of electrons between atoms to form a molecule but what is a chemical bond the definition for chemical bond that you need to know is a chemical bond is a mutual attraction between two atoms resulting from the simultaneous attraction between their nuclei and their outer electrons it's basically a force that holds the atoms together in a molecule now we will get into bonding and how the attraction how the attractive forces work and the repulsive forces work and how that affects bond energy and bond length in another video in this playlist but in this video all I need you to understand is that it's a mutual attraction between two atoms so if you look at the little diagram I drew over here this represents an atom atom number one we've got positive protons in the nucleus and we've got negative electrons that surround the nucleus in the outer orbitals this is atom number two over here again positive protons in the nucleus and negative electrons in the orbitals that surround the N the um nucleus now basically what they're saying is that it's a mutual attraction between two atoms the positive protons here are attracted to the negative electrons of the other atom and vice versa you can see here the negative electrons here are attracted to the positive protons there and basically what happens is these atoms move move closer they move at an optimal distance from one another when they where the energy is the lowest we'll get to that in the next video and then they form a bond it's a force holding the two atoms together and this is essentially what happens atoms Collide the outermost electrons the veence electrons come into contact with one another first the positively charged nucleus pulls on the veence electrons of the other atom as I mentioned and this creates a force now we will go through this in more detail as I said in other videos in this playlist but this is essentially what happens there's an electr I force between the different charged particles there's attractive forces there's repulsive forces and basically they find an optimal distance between them where the energy is the lowest and that's when the bond happens and it says here atoms will bond if the molecule that forms remember a molecule will be a combination of two or more atoms so if the molecule that forms has a lower energy a lower potential energy than what the separate atoms have Okay so separate atom has an energy a potential energy separate atom has a potential energy you add those two energies together you get a value if they form a bond and that energy of that combination is lower than what it would be separately then they will want to form the bond the reason why is because the lower the potential energy the more stable so sometimes it's more stable for them to be together than for them to be apart and I briefly did mention bond energy and bond length but again we will get into that in more detail in another video and this is what the graph looks like so the potential energy graph versus the distance between the nuclei again check out the links in the description box below for more videos on this but I just want to to have a basic understanding of what you can expect in this playlist so this is what's coming up so Atomic combination chemical bonding so what we did is we just defined a chemical bond and now you understand why a Bond happens and a brief description about how it happens other things that will be coming up are so firstly different types of chemical bonds leis do diagrams to represent coent bonds this is very very important you need to know to draw different types of Le do diagrams and I'll be showing you how to do that graph for potential energy versus distance between the nuclei briefly discussed in this video but we'll go into it in a lot more detail and related to this will then be bond energy and bond length and how this um these two things vary with different sizes of atoms and things like that then we'll be looking at molecular shapes using this model electro negativity and change in electro negativity and flowing from that so based on that we work at the polarity of bonds using difference in electro negativity and from that we use that information to help us determine if a molecule is polar Co valence or non-pov valent all of these things fit together so all of these topics flow from one to to each other so you need to watch the entire playlist make sure you go through all the different subtopics because if you're missing a piece of information then the next subtopic won't make sense I'll see you in the next video Everybody bye