hello and welcome so today we're going to talk about veence electrons veence electrons in my view are the most important electrons when talking about chemistry they are on the outside of the atom which means they're accessible for doing chemistry that is to say uh making bonds breaking bonds they're involved in bonds connecting atoms together and as we'll see um in a different time we'll talk about how electrons they can either be shared or you can transfer electrons between atoms in the process of forming ions but all those processes of making or breaking bonds of doing chemistry has to deal with the electrons that are on the outside and those are called the veence electrons all right um versus a core electron a core electron these are electrons so close to the nucleus they are so attracted to the nucleus that they're basically not available for too much of chemistry so our Focus from here on out uh is going to be veence electrons all right so we have to figure out where they are where do we find these veence electrons all right so I got some goals for today um we already talked about what a veence electron is um we already talked about um where they can be found we'll have a little bit more to say on that and then we're going to talk about something called an orbital shape all right um I'll do just leave that as a question mark for now and then we're going to close with using the periodic table to predict orbital shape all right let's go all right so first this is a very important idea which is where do we find electrons on an atom said another way would an electron be as close as possible to the nucleus or would electron be better off far away um well electrons don't really get to choose maybe that's the wrong way of putting it we're just trying to think of what nature does automatically so we have a positively charged nucleus with the protons inside and then we have electrons negatively charged so to maximize um attraction electrons will go towards the nucleus they're going to be as close to the nucleus as physically possible all right um so a question might become is electron going to be right on the nucleus is there maybe some space um so we'll get there but uh the the basic idea here is electrons go as close to the nucleus as they possibly can that's just what nature does all right and we have a name for this this is called the ground state just like you don't see me um floating around in this room um I am sitting I am uh on the ground okay so just like objects go to the ground o that was too loud um objects go to the ground uh so do electrons that go to the ground or it's the nucleus all right if you were to push an electron away from the nucleus that can be done through uh putting energy into electron that can be done through various things like heating up your atoms so just heat electrical current you can even hit the electron with photons push it away after you put in that energy that electron is going to find its way right back to be as close to the nucleus as possible but when that electron is momentarily pushed away we call that an excited state all right most of our conversations here are are going to revolve around electrons being in the ground state in other words we're going to be talking about ground state atoms okay now we're trying to form a physical picture of how electrons uh are arranged on an atom okay in an earlier video I talked about the bore model so uh in the bore model you imagine electrons moving around as like planets go around the Sun um and you would maybe call them orbits so if electrons had to travel in orbits hopefully it stands the logic that it would be in the closest orbit possible so that it is um as attracted to the nucleous as it can be all right and that would be our so-called a default position all right that's where the the electron is happiest most stable um good stuff um lowest energy if you want to use physics terms all right and like I drew in the similar SL uh the previous slide an electron further away we had an outer orbit it would find its way to going back to the closest orbit possible again that's ground state versus um excited state all right but our orbits really the way electrons exist and the answer is no all right this is where um chemistry can feel a little bit strange and weird but we're going to try to simplify it so electrons right let me put it this way visually all right if you were to draw a nucleus and then you were to draw um where an electron could be at any point in time if I were to let this run after like a 100 200 different points in time or maybe a million um just a lot um hopefully you get the idea you would got to plot something like this all right um and you can see that the number of times the electron is close to the nucleus or even inside a nucleus is much higher compared to being away all right this is like a probability plot all right the way we interpret how electrons behave or the way we have equations that describe electron Behavior this probabilistic way of describing the electron seems to be um one of the uh best ways of describing where we can find the electron all right and electrons move fast all right uh not quite the speed of light but you're almost uh approaching it you know um so uh where're we're going at fast speeds and so you plot this many times a 100 times a thousand times million times billion of times you'll eventually just kind of see that after so many different spots uh we can just draw something more practical we can draw a uh sphere okay and in this sphere it shows 90% of time the electron can be found in uh this space here all right um so you study like shers equation and probability stuff like that um for a one1 course that's certainly not required but we're going to study those things um the the electron technically speaking this is a little weird but it has a really slight um possibility of being like really away from the nucleus um you can go out to a distance of infinity and you know there there's like maybe if I were to draw this as a graph okay if I were to draw this as a graph and I have like distance going this way R is for radius if you're like to start at the center of the nucleus all right I'm covering that all right so here's my graph our distance and then we had like a probability of finding the electron you can see uh if I use this part um being in a nucleus as the highest level of probability and then we're going further away you can see that we're at high probability oh it's going lower lower lower lower lower gets really low and then you get uh the fancy math word is ASM toote um someone's going to look up that word ASM toote all right I don't really say to PE too much but um it's like about to touch a line but it like never does all right and so you can see by the time you're quite far from the nucleus basically practically speaking practically speaking you have zero probability all right uh to get a reasonable shape though uh some people they'll just choose to draw their uh shapes at like 50% I kind of like 90% um I don't I shuffle in between sometimes that percentage actually isn't overly um important but we can get these um more practical shapes you can see how that ends up being just a simple sphere and we can call that the electron cloud a lot of people like to talk about how electrons they're moving so fast is basically the entire blur the entire blur of the electron motion um that's just your Cloud all right and you can basically think of that as the electron itself that's the way I basically like to think of it all right and so yeah uh that's how we're going to draw these orbital shapes okay so rather than electron going in orbits we now have these orbitals which um come from Solutions of What's called the Schrodinger's equation again I would never put this on a one1 exam but it's all based on the mathematics that describe the data best of where we find electrons in atom so it's all rooted in the math describing the physics of of the atom all right so you can look up stroger's equation but that's that's where all of this is coming from for one inone purposes I want to keep this as straightforward as possible so just for those interested I wrote that there but we'll we'll just move on all right so this is where uh I think it's kind of cool and weird um the sphere is kind of a intuitive shape all right and um for when you're starting out describing electrons let's say we're talking about the most simple atom possible a hydrogen atom you get uh these uh sorts of shapes all right and that first electron the only electron for a neutral hydrogen atom it'll exist in this kind of spherical uh space But as we'll see uh later on in um the next video um we're going to have these other shapes that are possible all right and so we can have spherical shapes for the electron orbitals um I never describ where the word orbital comes from orbital is just we call it orbital because we know it's truly not orbit so we just said H let's just use a similar word so that's where orbital uh came about but we can have these spherical orbitals we can have these uh dumbbell shape or figure8 shapes and you can just kind of see in terms of the number of like lobes uh we go from one area of space um area of space that's an oxy more whatever uh one one space to like two spaces and then we go to four and then we go to eight that one's hard to draw the double Clover sphere dumbbell double dumbbell or Clover and then we have a double Clover or you can say a double double dumbbell where we have eight possible regions and these shapes are really interesting like uh for the spherical shapes uh you can have um electronic exist like literally in the nucleus okay uh whereas for a dumbbell shape you can but basically just at one exact uh Point um and anything outside of the shape you're not going to have the electron exist in those spaces that kind of has to deal uh with the wave nature of the um of of electrons all right this wave nature of matter that becomes Apparent at really small uh distances okay and so like if I were to draw a sine wave okay sine wave okay like a sinx function right you get something like that all right you know you you have um area here you have area here but right here you have no area so we call that um a node we have a node right there but that's a 2d wave these uh wave functions for describing electrons they're in three dimensions all right so um if I had blown up some balloons oh I should have done that but if I blown up some balloons and I tied two of them like together it'd be kind of like that if I took two of these balloons and tie them together I'd get that and so on um so forth all right now these orbital shapes are not terribly important uh in chem 101 other than to know that they exist and some chem1 one courses maybe they'll stop right there some might stop right there now I used to be a uranium chemist and so I had to deal with f electrons a lot so I like to draw those I wouldn't put that um on the test that's hard enough for me to draw all right but practically speaking knowing the orbital shape can begin to give us and here's our my final slide for today um some sense of organiz ization of the periodic table all right so I drew four different regions here and I can take my real periodic table okay we have um different block names here so this is called the S block this is called a p block this is called a d block and then this last part that we had to move out so it could fit into a single sheet of paper all right let me get that camera moved there we go uh this is the F block all right and as I'll remind you in the next video uh it's good to think in that order s PDF spdf the special PDF file is my little uh nickname for it all right if you're wondering why that order well the numbers tell us so one starts in the S block where with hydrogen helium as we'll talk about a little bit more later but it it actually belongs um when we're talking about electron Arrangements I'd say helium might be better off right here because it has also another s electron um if you know something about noble gases maybe that's why uh helium's here um and that is why I I like to call helium a dual citizenship element all right it likes to hang out here because it's a noble gas but this is where it came from all right uh but yeah one two and then um three four and then five that's our first P block element so we want s p and then potassium 19 calcium 20 Scandium 21 so the D Block appears third and [Music] then cesium barium 55 56 and then 57 lanum serium pradini so on so forth here is our F block appearing last all right and yeah that's the power of the periodic table another another one of its powers is based off of where an element is on the periodic table whether it's the s p d or F block you'll have an idea of what those electrons those orbital shapes look like for the veence electrons the electrons on the outside all right the next video we will put this together by uh showing the address for these electrons you're going to write out um an address a map whatever you want to call it for every electron in an atom and after you write that all out you will know which electrons are the veence electrons which electrons are the core electrons veence and core we're we're going to do that through writing things called orbital diagrams and electron configurations but I think this is a good stopping point all right all right hope this helps and let me know if you got any questions take care