in this video we're going to discuss the difference between ionic and calent bonding in ionic bonding electrons are transferred from one element to another and typically ionic bonds contain ions in a coent bond electrons are shared but let's go over ionic bonding first let's consider the reaction between an atom of sodium and an atom of chlorine sodium as an atom has one veence electron if you look where it is in the periodic table it's in the First Column it's in group 1 a of the periodic table and elements in that group all contain one veence electron a valence electron is simply the electrons in the last or outermost energy level chlorine which is a hogen contains seven valence electrons it's in group 7A of the p table the halogens are very reactive non-metals and the alkaline metals where sodium is found are very reactive metals metals like to give away electrons and so they form positively charged ions non-metals they like to receive electrons and so they form negatively charged Anns so sodium is going to give chlorine one of its uh electron or valence electron since it only has one so as sodium loses that one veence electron it's going to acquire a positive charge and as chlorine gains that electron it acquires a negative charge now going back to physics if you have two like charges next to each other what's going to happen like charges repel they're going to feel an electric force that repels them or pushes them away from each other but what's going to happen if you have a positive and a negative charge next to each other these two are attracted to each other they feel a force of attraction that pulls them together and so that's what's happening between the sodium ion and the chloride ion the sodium ion which now has a net positive charge is attracted to the chloride ion which has a negative charge and so these two they feel a force of attraction and that force of attraction that electrostatic force it binds them together and so that creates the ionic bond so keep this in mind within ionic bonds you have a transfer of electrons and the bonds that hold them or as a result of the electrostatic forces between opposite charges keep in mind opposite charges attract each other so now let's move on into Cove valent bonding let's look at hydrogen a hydrogen atom has one valence electron and it's in the first row of the periodic table elements in the first row they want to have a total of two electrons in their outer energy level second row elements they want to have eight electrons so elements Like Oxygen and Florine they want to satisfy their oxide they want to have eight electrons but hydrogen and helium they can only have two electrons in that first shell so each of these hydrogens they need one more electron to fill that first shell with a total of two electrons and both of these elements are the same so what they're going to do is they're going to share their electrons and so these two they're going to form a bond so when you see a bond this Bond represents the sharing of two electrons and so this is a calent bond anytime you have sharing of electrons it's a calent bond now there's two types of calent bonds you need to be familiar with polar calent bonds and non-polar coent bonds the bond between two hydrogen atoms is considered to be a non-polar coent Bond the reason why it's non-polar is because the electrons are shared equally between those two hydrogen atoms now if you look at the bond between hydrogen and Florine the elements are different Florine is much more Electro negative than hydrogen because Florine is electr negative it's going to pull the electrons toward itself now granted the electrons are still being shared but they're being shared unequally and whenever you have an unequal sharing of electrons you have a polar coent bond as opposed to a non-polar coent Bond so because Florine is more electronegative as it pulls the electrons toward itself Florine is going to acquire a partial negative charge and hydrogen is going to be partially positive and whenever you have an object where one side is positive and the other side is negative you have a dipole you have a polarized object and this is what it means to be polar you have an unequal distribution of charge one side is positive one side is negative so the electrons they're not distributed evenly in that molecule the electrons spend more time closer to floring because it's more electronegative electro negativity is the ability of an atom to attract an electron toward itself and Florine it does a good job in doing that so now you know what a polar calent bond is it's a bond where you have unequal sharing of electrons and a non-polar coent bond is a bond where you have equal sharing of electrons now let's go over some practice problems I want you to classify the following bonds as being ionic polar equalent or non-polar Co valent so let's start with the first one MGO magnesium oxide is it ionic polar coent or non po Co valent the first thing I would look for is to see if it's ionic typically an ionic compound consists of a metal and a non-metal that's how you can easily identify magnesium is a metal Metals exists on the left side of the periodic table non-metals exists on the right side the nonmetals are on the upper right side the metals are on the lower left side so magnesium is a metal and oxygen which is on the upper right side of the periodic table that's a nomal so this is going to be ionic magnesium forms a plus two charge as an ion it has two valence electrons so in this bond is going to give away two electrons to oxygen oxygen which is a calogen magnesium is an alkaline earth metal but oxygen it has six veence electrons it needs two more to get to so once it acquires those two electrons it's going to have a negative charge as you can see this compound is composed of ions now what about two chlorine atoms chlorine is a netal whenever you have two nonmetals with the same type of element it's always going to be a non-polar coent the electrons are shared equally because we have the same type of atom now what about sod floride sodium is on the left side of the pic table so it's a metal and Florine is a hogen on the right side so that's a nonmetal so sodium fluide contains ionic bonding now what about hbr is it polar calent or non-polar calent now the elements are different so that could be an indication that it might be polar equalent but you need to run a test you need to calculate the difference in electro negativity if the electro negativity difference is equal to or greater than 0.5 most textbooks they use this number if it's 0.5 or more then the bond is considered to be polar coent if it's less than 0.5 if it's 04 or less then it's considered to be non-polar coent so if you need the electro negativity values you can go to Google images and type in uh electro negativity table and you'll see some tables come up now i' seen different tables with different values they don't vary much but sometimes they do vary so if you're doing a homework problem use whatever table your book gives you in the table that I use hydrogen has an electro negativity value of 2.1 bromine it's about 2.8 and so the difference is 7 therefore this is going to be polar coent I'm going to write PC for Polar coent now what about iodine monobromide what is the difference in electro negativity iodine has an electro negativity value of 2.5 and for Bromine 2.8 so the difference is about3 which means that that it's relatively non-polar coent so I'm going to write NC again make sure you use the table that your book provides because if the values are slightly different the result might be different but the idea is that you want to find uh an difference of 05 or more to see if it's polar or not so let's try some more examples determine if the following bonds is polar coent non-polar Co valent or ionic so let's look at carbon and hydrogen carbon has an electronegativity value of 2.5 and for hydrogen is 2.1 so thean difference is4 for this one I would commit this memory anytime you see carbon and hydrogen it's going to be nonpolar this is a very common example that you see within chemistry and even organic chemistry now what about the O Bond whenever hydrogen is bonded to oxygen nitrogen or Florine you have a special case of bonding known as hydrogen bonds whenever you have hydrogen bonds it's going to be polar by the way oxygen has an electro negativity value of 3.5 so 3.5 minus 2.1 the difference is huge it's 1.4 this bond is very polar so this is polar coal this is nonpolar coal now if the two atoms are the same and they're both nonmetals it's going to be nonpolar coent you don't really need to do the calculation Florine has an electro negativity value of 4.0 4 - 4 is 0 Which is less than 0.5 now calcium sulfide for this you really don't need the electr negativity values you just need to know that calcium is a metal and sulfur is a nonmetal and then so you could say it's ionic if you have one element all the way to the left side of the P table and another all the way to the right side it's going to be ionic so that is it for this video now you understand the difference between ionic and coent bondet so thanks for watching and have a great day