next type of true chemical bond and hopefully you know the answer just we set our ionic bonds these are going to be between a metal usually just one of the ones over here that we see and a nonmetal something from over here and ionic bond form so they're very very stable when dry but they fall apart in a local environment so an ionic bond as we said atoms are going to steal or give up entirely their electrons and this makes both atoms involved in the bond happy because they still get their full outer shell of the electron and the classic example of a bond held together this way is table salt sodium chloride right okay we'll let's look at why why this happens so entry for sodium entry for fluoride so how many electrons and then how many valence electrons for both of these and if I don't give you enough time in my little pauses to work this out remember you can always pause the video and work it out and again I strongly encourage you to work it out don't wait for me to give you the answer because it's nice to have time on your own to be you know working on okay so the number of electrons is a ton charge equals the number of protons of course we're getting to the point where these guys have a charge right that's what anion is is a charged atom a molecule whether the moment our number of protons which is given in your atomic number equals in the Merve electrons and then the valence electrons we start off by subtracting two so 11 minus 2 giving 9 I subtract eight for the second shell and that leaves me with one just one little little electron over here so we start off with 17 minus two years make fifteen electrons left over right to go in the first shell 15 minus 8 gives me seven so third shell will hold up to 8 so valence electrons are going to be 7 I'm going to draw out all of these electrons just to give you an idea of what's going on here because remember what these atoms want is a full shell of valence electrons so sodium I'm going to put two electrons in the innermost shell and then I'm going to put eight out here 1 2 3 4 5 6 7 8 and then outermost shell just 1 and maybe you've been taught to do bonds this way where you draw all the electrons and that's just fine rather than the sort of slightly simplified Lewis dot structure that I showed earlier if this helps you keep Chuck go for it the reason I wanted to draw this is let's think about the easiest way for sodium to get a full shell of valence electron what if it just takes this electron and gets rid of it what if it dumps that electron and then the next shell in is full that's the easiest way with the least difference in charge for sodium to get a full outer shell it can give up an electron where's it going to give it up to it's going to take something like chloride which is very very reactive and the reason chloride is very reactive is look at how many valence electrons it has it has seven and it wants eight it just needs one more right it is like super desperate all I need is one to complete the set and so it is really going to be good at stealing an electron even more so than oxygen and in fact if you look at the three otic table fluorine and chlorine are both very very reactive gases and are really good at stealing electrons and this is part of these like pouring to clean swimming pools and stuff because of that that tendency and they are even further to the right of oxygen which is really good at also hugging electrons but doesn't actually steal them it's not like that either so if Corrine could just steal one more electron I'm not going to draw all this electrons I'll just draw is beyond electrons in this case one two three four five six it has seven so what it just steals this one electron and it will fill it set right everybody ends up being happy so sodium gives up an electron and chlorine steals an electron well if you do that you don't have a partial charge anymore if you entirely give up an electron you have a hole on charge right if you give up a negative charge sodium is going to end up with a plus one charge it is an ion right and we're talking about ionic bonds chlorine which has just stored an electron does get some extra negative charge and that's maybe more obvious to see and so it gets a minus one charge remember ion when I draw the little negative sign next to my atomic symbol that tells me that it is an ion is a charged atom and these guys are attracted to each other right I've got a bus I've got a - all bandits attract so what holds together ionic bonds are the attraction between oppositely charged ions and they become oppositely charged because these two atoms interact right and one of them will give up a lot of times when and will take those electrons and these as we said ionic bonds are the equivalent of white paste they are going to come apart in water because water we just saw is a polar molecule right and oxygen is slightly negative so it's going to be attracted to these slightly positive sodium's and the hydrogen's in a water molecule are slightly positive so they're going to be attracted to this negatively charged chlorine so these are the white paste bonds they fall apart in water so our second type of true chemical bonds are ionic bond I would take some time and maybe practice with other types of ionic bonds they just form you could also have safe to taffy and chloride right and you can see at what type of bond that would form I let's see I can give you a few other examples of ionic bonds that we can practice with in class how about so ionic bond not as strong as covalent bonds but still fairly strong bonds and the result of stealing and gaining electrons