covalent bonding we discussed ionic bonding in the previous chapter we are supposed to discuss covalent bonding in this chapter kubern bonding is actually a pair of electrons shared between two atoms now what is going to hold that because in ionic bonding we were discussing strong electrostatic forces of positively charged particles with negatively charged particles covalent bonding is somewhat different a shared period of electron is right in between two nuclei and nucleus of a is attracted to the electron pair nucleus of b is also attracted to the electron pair shared pair of electrons bonds from each atom so the number of attractive forces are actually still higher than the number of repulsive forces which keeps the both the atoms intact and hence the covalent bond so let's discuss a few uh examples in order to make it easy covalent bonding in a hydrogen molecule covalent bonding is also shown with the help of dorian cross diagrams but this time we're not going to lose electron from one atom and gain in the other instead we're going to share electrons and what we are going to do is draw circles sharing those electrons which are going to overlap one another in order to show the share hydrogen atoms form diatomic molecules with the formula of h2 means a molecule has two hydrogen atoms and each sharing one electron the atoms of hydrogen molecules are joined together by a covalent bond the covalent bond between hydrogen atoms is very strong because of the nucleus able to attract the shared pair of electrons now molecules contain certain fixed number of atoms which are joined together by covalent bonds hydrogen molecules are said to be diatomic because they consist of two atoms other sorts of molecules have as many as thousands of atoms joined together for example proteins or dna remember that although the electrons are drawn as dots or as crosses there is absolutely no difference between them in reality the dots and crosses are simply the illustration that tells us where the electrons come from in two different atoms the significance of noble gas structures in covalent bonding in h2 each hydrogen atom has only one electron to share so it can only form one covalent bond the shared pair of electrons is in the outer shell of both therefore each atom has the same number of electrons as a noble gas nearest noble gas helium in this case now let me explain that a helium atom has actually two electrons in its outermost shell one over here one over here and it has noble gas configuration for the first shell so hydrogen atoms if you take a look at them they will have two electrons after they have made the sharing the both electrons will actually revolve on both the atoms this they will go over here so this atom would consider having two electrons and then they will go like this this atom would also consider having two electrons so both hydrogen atoms would seem like they have the nearest noble gas configuration in the specific gas helium let's clear it up move forward so virtually all of the molecules you'll meet at this level electrons would be shared so hydrogen atoms have a total of two electrons in their outermost shell as this is the partial all the atoms will have eight electrons in the outermost shell some people talk about the octet rule referring to this eight octa means eight octet rules means they have eight electrons in their outermost shell to have the nearest noble gas configuration or the stability we're talking about neon first 20 atoms as we discussed in the previous chapter now if atoms have eight electrons in the outermost shell they have the same number of electrons in the noble gas atom their isoelectron with noble gas atom remember neon now if there is one atom in the middle and other atoms are joined to it as ch4 or pcl3 the outer enzymes will virtually always have eight electrons in their outermost shell or two if they're hydrogen because in that case we're not talking about octet rule actually in case of hydrogen or in case of hemium we what we talk about is duplet rule the rule for eight electrons in outermost shell is octet rule the rule for two electrons in an alpha motion which only goes for the elements of uh the first period of the periodic table is the platoon so two if they're hydrogen in fact it's very difficult to think of an example where the outer atoms do not have eight electrons there are some molecules where central atom does not have eight electrons in the outer shell and we'll discuss those examples a little later in the chapter moving on why does hydrogen form molecules whenever a bond is formed or whatever kind energy is released and that makes the thing involved more stable than they were before the more bonds an atom can form the more energy is released and the more stable the system becomes so h2 molecule is much more stable than the hydrogen atom or two separate hydrogen atoms so remember the need for bonding is basically the stability and by burning atoms become stable in the form of either molecules or if there are any compounds in the form of formula units or whatever the kind of corner is now remember in chemistry we talk about things being more stable or less stable when we do this we're usually talking about how much energy something has generally the lowered energy something has the more stable it is chemical reactions usually occur so that something becomes more stable think about holding a bit if in the toe of the book it will fall to the floor where it has less potential energy therefore it becomes more stable when bonds form energy is given out and so the substance form has less energy and we call it more stable so all of the morning beat ionic bonding covalent bonding or any other kind of bonding it's all about becoming more stable and whenever we talk about atoms having the electronic configuration of the nearest noble gas that's once again about stability as so covalent bonding in a hydrogen chloride molecule this time we're not considering to consider a molecule that has same kind of atoms this time a molecule which has different kind of atoms it's made up of one hydrogen and one chlorine atom the chlorine atom has seven electron in its outermost shell by sharing one electron with hydrogen atom both atoms will have same number of electrons as the nearest noble gas now what that means for hydrogen is it's going to have the configuration of helium and what that means for chlorine is the configuration of argon now helium has the configuration of two which hydrogen has achieved by sharing the electrons and this time chlorine has the configuration of argon which is actually 2 8 8 and again it becomes stable this way so what happens after sharing the electrons they have the configuration of the nearest noble gas they become stable by sharing the electrons and outermost shells get complete with respect to octet or duplet rule in other elements all other elements and in hydrogen respectively now in figure 8.4 you'd notice the electrons in the outer shell of the chlorine are used in bonding in the examples you will meet at igcse and electrons never get used so the fact that inner electrons are often left out of the bonding diagrams so that's easy that makes the whole drawing thing easy but be careful in an exam only leave out the inner electrons if the question tells you to another way of representing the covalent bonding in hcl is shown in figure 8.5 let's move on to figure point five so that's it you just show the outer shell electrons and that's about it now this specifically states throwing out which has electrons only so once again be vigilant when you're reading the question and make sure that you go with the diagram that examiner has asked you to draw now we can also use lines to represent covalent at bonds between atoms but be careful the diagram shown in figure 8.6 is not a dotted cross diagram so this is a more of a structural diagram now whenever he's going to talk about the structure this is the structural diagram and these are current cross diagrams 8.4 and 8.5 respectively showing all electrons and outer shell electrons on so there are many ways to represent the covalent bonds and make sure you represent them the way the examiner has asked you to moving on covalent bonding in a chlorine molecule is pretty simple again it's a sim single bond one bond only where there is a sharing of one electron from each of the chlorine atoms both the chlorine atoms within have eight electrons in their outer motion after sharing this one so this is the entire structure this is the structure which just the outer shells and whenever you need to draw it with the help of a structure it can simply be this and the chemical formula becomes this so that's how we go with it let's discuss some other structures a little bit bigger structures covalent bonding in methane ammonia and water now methane ammonia and water all consist of hydrogen but apart from a hydrogen methane will have carbon ammonia will have nitrogen and water is going to have oxygen so their electronic configurations are shown first let's move on so first of all methane carbon has four electron in its outermost shell in order to go for the octet rule it requires four more electrons so it shares it with four separate hydrogen atoms as you can see over here and a single bond with each of them would get the trick done and hence this is the structure of methane it can be drawn like this in case of structure the diagrams given in 8.9 are dotted cross models for the entire structure or just with the outer electrons on methane has the formula ch4 moving to ammonia nitrogen has 5 electrons in its outermost shell therefore it requires to share three hence uh three separate single covalent bonds with each of the hydrogen atoms and that's this kind of structure we can separately draw it like this in case of ammonia you'll be amazed to see that apart from this structure there is a pair of electron that is present as a part of outermost shell but does not participate in bonding which is drawn right over here on the top of ammonia we are going to later call the spear as lone pair this is to differentiate this pair from these three pairs which are all actually known as shared pairs you may also call them bonded pairs this is a way to differentiate the electrons so if that's present as a part of outermost shell and participate in bonding they are known as shared pairs or bonded pairs but if the electrons are present as a partial part of my shell and do not participate in burning they are known as lone pairs moving on to the structure of water oxygen has six electrons in its outer motion so what happens is that it's going to only share two and complete its octet eight electrons in that's outdoor shell one with each hydrogen atom so the formula becomes h2o and you would see that it has two known pairs and it has two bonded pairs or shared pairs right so shapes of molecules methane and water has been drawn differently than what we can see over here a methylene molecule is tetrahedral a water molecule is bent so by understanding the bonding in a covalent molecule that is possible to work out the shape of the molecule pairs of electrons in the outer shell of the central atom repel each other and will therefore tend to get as far apart as possible for example in a methane molecule there are four pairs of electrons around the central c atom and for these to be as far away as from each other as possible they must be arranged in a tetrahedral shape a tetrahedron is a triangular pyramid so they are far apart from one another in this case there are also four pairs of uh electrons around the central atom in water two of these pair of electrons involved in covalent points and two are pairs of electrons in the outer shell of oxygen which are not involved in bonding let me draw it again for you two of the pairs are purely oxygen and two of them are shared pairs which are in equivalent bonding with the hydrogens atoms these are often called in pairs or just lone pairs of electrons uh the four pairs of electrons are also arranged in a tetrahedral arrangement so the actual shape of water molecule is described as bent or v-shaped the fact that water molecule is bent and electrons are attracted to different extent by oxygen and hydrogen atoms means that a water molecule is polar has a slightly negative and a slightly positive end and that a stream of water can be bent by electrically charged object as you can see in this diagram so they are going to have a little bit of charge not complete charges in them a little bit of charge and we are going to use the word polar for that purpose moving on covalent bonding in a slightly more complicated molecule ethane ethane has the formula c2h6 to carbon atom six hydrogen atoms now there is a carbon-carbon covalent bond involved however there are a lot of carbon hydrogen covalent bonds involved in there take a look there is only one carbon carbon covalent bond however there are one two three four five and six carbon hydrogen bonds this is an organic compound we're going to study it in unit four organic chemistry and it's mainly made up of carbon as the central element when drawing molecules containing carbon and hydrogen it is useful to remember carbon always form four bonds by sharing four electrons and hydrogen always forms one bond by sharing one electron not just that if you are going to go with this hint you better also note that hydrogen is uh sorry nitrogen is going to form three bonds carbon is going to form four oxygen is going to form two and hydrogen and all of the halogens i'm going to represent hydrogen with h but all the halogens with x are going to form one bond each so if you know the number of bonds it is going to be easier for you to work them out in turn cross diagrams let's move on multiple covalent bonding now covalent point is not just about sharing one pair of electron it can share more an oxygen atom has six electrons in its outer shell so if two oxygen atoms combine they will both share two electrons each this means that each atom will have eight electrons in the outermost shell therefore two shared pair of electrons between the oxygen atoms represent a double covalent bond or we simply call it a double bond a double bond is actually four electrons shared between two atoms and is shown by a double line like this this is for oxygen molecule so multiple bonding includes double bonds and triple covalent bonds next example is a triple covalent bond between nitrogen atoms and nitrogen has four electrons uh sorry five electrons in its outermost shell and if two nitrogens are supposed to combine they will both share three electrons each and that would become a sharing of six electrons between two atoms which is a triple covalent bond and shown by three nines each atom shares three electrons it's known as a triple bond nitrogen gas consists of nitrogen molecules pointing like this the triple bond from the sharing of three pairs of electrons between two nitrogen atoms is very strong needs a lot of energy to break that's why nitrogen is relatively unreactive and that's going to go for true for all the triple bonds they're going to be strong and in order to break them up will require a lot of energy now double bonding can also be explained for carbon dioxide carbon has four electrons in its outermost shell oxygen has two and oxygen only needs to make two bonds in order to have its octet complete while carbon does four so you would see that carbon is making two double bonds one on each side with each of the oxygen atoms while oxygen is only making one double bond per atom so that stabilizes oxygen for its octet as well as carbon for h1 so that's this kind of structure for carbon dioxide moving on the double bond in athene ethene is rather like a pain except that it has has two hydrogen atoms attached to each carbon atom because there is a carbon-carbon double bond instead of carbon-carbon some single bond unlike a pain so there is a double bond in between and carbon are sharing four electrons into plural between two atoms two electrons per atom and there are the hydrogen atoms that are attached to it with single bonds with organic compounds such as ethane and ethene you'll have to look at their names very carefully even one different letter in their name can matter ethan and athena completely different compounds so a mistake of vowel and there you go everything seems incorrect moving on organic molecule contains halogen atoms bromomethane has the formula of ch3br three hydrogen atoms and one bromine atoms join at the central carbon atom bromine has 35 electrons and we have not learned how to work out electronic configuration of atom with 35 electrons but if we know from the periodic table and bromine is present in group 7 it has seven electrons in its outermost shell so it's pretty much going to behave like chlorine of fluorine in this case it will only share one electron form a single covalent bond and will satisfy its octave if you take a look at it this would be the structure of bromo methane which is ch3br probably more complicated the most complicated molecule for which you could be asked to draw a diagram would be something like chloroethylene when drawing fluorescein remember that carbon will form four covalent bonds hydrogen form one fluorine with one that is something i've explained earlier so i think it's going to be pretty easy there are four electrons in between carbons to form their double bond so every hydrogen is going to connect with a single bond on two single bonds per carbon atom actually so hydrogens two of them with one carbon and one hydrogen and chlorine with one carbon satisfies and there you go you have the structure for chloroactin so dot and cross diagrams are somewhat easy if you're only working with the outermost shells the structure of chloroethylene probably is the most difficult one however any kind of structure can be worked out if you know how to balance the octets or duplets for specific elements and you know how many bonds it's going to form to get stabilized by completing the octet or duplet so if you remember carbon four bonds nitrogen three bonds oxygen two bonds hydrogen and halogens one bond each it would be easier for you to form any kind of structure in the similar way moving on some more difficult molecules where the central atom does not have eight electrons in its outer shell it may have less may have more so let's discuss both type of examples bf3 boron trifluoride is an example of having less electrons in the outermost shell boron is the central atom fluorines are the outer atoms each fluorine will share one electron each to complete its octet as it has seven electrons in their outermost shell boron however has three electrons in its outermost shell it tries to share all three and still not able to complete it of its octet so boron actually in this case you will find that boron has only a total of six electrons even after shearing so this is the kind of example in which central atom does not have complete optic let's move on to the kind of example where center atom has more electrons what there are supposed to be an octet or more than eight electrons simply speaking sulfur dioxide or sulfur four oxide the central atom is sulfur the outer atoms are oxygen there are two oxygen oxygen has six electrons in their outermost shell they're going to share two each to make a double covalent bond that's what they do with sulfur so sulfur is capable of forming a double covalent bond with oxygen over here and with oxygen over here if it was just these two double covalent bonds this would have worked life like carbon dioxide and the structure would be stable with having the central atom also in complete octet but unfortunately in the case of sulfur it's not in group four it's in group six so there are still two extra electrons left out even after these double bonds so sulfur actually has 10 electron in its outermost shell which is more than eight which surpasses the octet rule in upcoming box in a levels we're going to have specific terminologies for these kind of atoms for these kind of structures the one which has less than the octet of less than eight electrons on ones which have more than the octet of more than eight electrons we're going to work them with specific names atoms in period three and below four five six seven can have more than eight electrons in their outermost shell maximum number of electrons that the central atom in a molecule can share is equal to the number of electron in its outer shell so sulfur can form up to six bonds and chlorine seven bonds sulfur six bonds the example is sf6 and chlorine seven bonds are example is hclo4 which actually are pretty much good examples of having more than eight electrons far more than eight electrons not just ten even more than that now let's come to simpler molecular structures molecules contain fixed number of atoms joined by strong covalent bonds if we look closely at liquid water there are individual water molecules where hydrogen and oxygen atoms are joined together with strong covalent bonds but there must be also some forces between water molecules which keep them in the liquid state these forces are known as intermolecular forces which exist in between the molecule so yeah there are strong covalent bonds which join hydrogen and oxygen atoms but the intermolecular attractions between the water molecules are much weaker and they connect the water molecules intermolecular literally means between molecules now intermolecular forces between molecules are much weaker than covalent bonds when we boil water it is only these weak intermolecular forces retraction that are broken covalent bonds are not broken so whenever we convert liquid water into gaseous water we break these intermolecular forces to allow the gas vapors escape the liquid surface the bonds covalent bonds between hydrogen and oxygen are not changed when a substance consists of molecules with intermolecular forces of attraction between them we say it has simple molecular structure examples of things that have simple molecular structures water carbon dioxide methane ammonia ethene these are all examples for those kind of structures we have drawn their uh dot and cross structures above virtually all compounds you will encounter covalent bonding will have simple molecular structures substances with simple molecular structures tend to be gases or liquids um sometimes really solids but no melting point in boiling points the reason for this is that not much energy is required to break the weak into molecular forces attractions if we compare them with ionic substances those were having a lot of strong electrostatic forces of attraction so they were always they were always solids here in case of colon bonds just the weak intermolecular forces hence mostly liquids or gases melting in boiling points increase as relative molecular mass increases the halogens in group 7 all have simple molecular structure consisting of diatomic molecules with intermolecular forces between them let's take a look starting from top fluorine going all the way to bottom chlorine bromine and iodine with formulas f2 cl2 vr2 and i2 respectively take a look that their relative molecular mass increases as we go down the series so does the melting point and the boiling point so much so that the state of matter will all will also get affected if we know the melting and boiling points we can always work it out this one is a gas at room temperature this one also is a gas at room temperature this one is a liquid at room temperature and finally iodine is solid at room temperature so the integral molecular forces actually change and so does the melting and boiling point which increase as relative molecular mass increases if you continue with chemistry you will learn that there are different types of intermolecular forces you will come across the terms like vendor wall forces london dispersion forces hydrogen bonds there is a special type of intermolecular forces between water molecules we call them hydrogen bonds hydrogen bonding gives water some of its very special properties for example the solid ice is less than than the liquid form hence floats on the top of the liquid form so moving on remember as we mentored boil these substances we're only breaking the intermolecular forces of attraction the boiling points increase down the group which means we have to put in more energy to break into molecular forces as the relative molecular masses increase the intermolecular force of attraction must become very stronger that's why the melting and boiling points are increasing this is something we see quite often in chemistry for example boiling point increase along the series ch4 c2h6 c3h8 we're going to study that in organic chapters and as the relative molecular mass increases this increases too now it is not always the case the melting point and boiling point increase as the mr increases and really the rule only applies to sets of very similar substances such as halogens or gains like the ones we discussed over here some examples where these rules don't work are water ethane ammonia and phosphene bh3 and you would see that they are very different instead of a boiling point increase there is a random decrease so this only goes with similar substances does not go with the entire periodic table or stuff like that some other physical properties of covalent compounds covalent molecular compounds do not conduct electricity molecules don't have any electric charges on them they are not ions all electrons are held tightly in their shared pairs they're not able to move from molecules to molecule so they are insulators do not conduct electricity covalent molecular substances tend to be insoluble in water some exceptions to this are ethanol and substances such as ammonia and hcl that react with water as they dissolve covalent molecular substances are often soluble in organic solvents and we've discussed that organic solvents can be ethanol or other such as petrol carbon tetrachloride so on and so forth giant covalent structures diamond is a form of pure carbon each carbon atom in diamond has four electron inside a motion and pong can form four covalent bonds but in diamond each carbon bonds strongly to four other carbon atoms in a tetrahedral arrangement now in methane we were actually connecting this carbon atom in the center with all hydrogen atoms but this one's different carbon is connected to other carbon atoms which are further connected to other carbon atoms and the entire structure goes into loop in its entirety carbon atoms keeps on continuing with their four covalent bonds all three dimensions hence we call the structure as a giant covalent structure it is not a molecule because number of atoms joined up in real diamond is completely variable and depends upon the size of crystal molecules always contain fixed number of atoms joined by covalent bonds diamond in turn because of this structure is going to have a high melting in boiling point because very strong carbon carbon covalent bonds which extend throughout the structure in the whole crystal in all three dimensions so a lot of energy has to be supplied in order to break these strong covalent bonds so this diamond has really has very high melting and boiling points it's important to realize this is different from the simple molecular structure we saw above such as ch4 or methane we only had to supply a little bit of energy to melt it off to boil it before we move on further a tetrahedron is a triangular based pyramid in a tetrahedral arrangement one atom is at the center of the tetrahedron and the atoms it is attached to are at the four corners look carefully the five top atoms in the figure is six eight point 8.26 if we look at it just the second this one is the central carbon atom it is connected to one two three and four carbon atoms all equally resistant to one another making sure that the electrons that repel each other are equally distant from one another and hence the tetrahedral arrangement again figure figured 8.26 some carbon atoms seem to be forming only two bonds or even one bond that's really not the case we're showing a very small part of it the whole structure has every carbon making four bonds each all single covalent bonds to four other carbon atoms and the structure in it in its entirety goes on with the same number of points so let's move on now we need a lot of energy to break the weak intermolecular forces of attraction in diamond there are no intermolecular forces it has a giant structure there are no molecules supplement bonds are very strong and must be broken in order to melt your boiled hence the high melting involving points in general all substances with giant covalent structures are solid with high melting in boiling points because of the large energy required other substances with giant covalent structures include graphite and silicon dioxide sio2 which are discussed below diamond is very hard again a lot of energy has to be supplied to break the bonds drill bits can be kept with diamond for drills used in stone and rock diamond can drill into anything because being the hardest natural substance diamond does not conduct electricity because all the electrons of outer shells of carbon atoms are tightly held in covalent bonds and they cannot move around as there are no ions and electrons to freely move the current cannot be carried hence diamond does not conduct electricity diamond doesn't even dissolve in water or any other solvent this is again because of a huge lattice a lattice that is made up of strong covalent bonds diamond conducts heats very very well better than any other element as one end of the crystal is heated the atoms vibrate more and more and the vibrations move on to other atoms the strong bonds throughout the giant structure mean the white these vibrations are quickly transmitted from one end of the crystal to the other and stamina is a very good thermal conductor but diamond is a very uh good electrical insulator graphite graphite is also a form of carbon but the atoms are drainage differently it also has the line structure but it has a layered structure rather than like a pack of playing cards the layers are on top of one another in a pack of card each card is strong but the individual cards are easily separated the same is true in the case of gray find which we usually use in pencils now atoms in the layer of graphite are hexagonally arranged so you can see six carbons on the six corners of the hexagon and the hexagons are connected together but if you have an edge on view of the layers layers are connected in between with weak forces of retraction between the layers the gaps between layers are much bigger than the distances between the atoms and layers so this is the structure of graphite because of this specific structure the hexagons the layers the weak forces between the layers but having a larger gap this brings the graphite its specific properties let's discuss a few of those graphite is a soft material all the forces holding the atoms together are very strong in each layer but the attraction between the layers are much weaker and not much energy is required we can easily push the layers and they slide over one another can easily be flaked off and the same thing goes around with the pencil and it leaves a trail we call it handwriting graphite mixed with clay to make it harder to be used in pencils when you write with a pencil you are leaving a trail of graphite behind on the paper poor graphite is so slippery that it can be used as a dry lubricant for example powdered graphite is used to lubricate locks now graphite has high melting and boiling points to metapoint graphite you don't have to separate layers you have to break up the whole structure including the covalent bonds which actually needs a lot of energy because the covalent bonds are very strong actually the reason that the layers slide over one another fairly easily is more complicated than this and graphite is not a lubricant in a world vacuum if right being a lubricant relies on water molecules sticking to the surface and this does not happen in a vacuum now graphite conducts electricity if you look back at the figure the edge on view each carbon atom is joined to only three others and each carbon atom uses only three of it outermost uh shell electrons to form three single covalent bonds the four electron in the outer shell of each atom is free to move throughout the layer so the electrons that are free to move are known as delocalized electrons and the movement of these delocalized electrons allow graphite to conduct electricity in between the layers graphite is also insoluble enough solvents because it would take too much energy to break all the strong covalent bonds if it does less than thin diamond because layers in the graphite are relatively far apart and the distance between the layers is more than twice the distance between the atoms in each layer and since clay factories will contain a lot of wasted space which there isn't any in a diamond crystal that's why diamond is dense and graphite is less dense as compared to it c60 fullerenes diamond and graphites are two other tropes of carbon allotropes are actually different forms of the same element because of having differently arranged arrangement of atom for example diamonds are tetrahedras carbon atoms and graphites are hexagonally layered arranged carbon atoms another electrode is carbon 60 fullerene diamond and graphite have both giant structures but c60 fullerene has a simple molecular structure only consisting of 60 carbon atoms in solid liquid c60 fullerene there are carbon 60 molecules with three intermolecular forces between them the fact that c60 has a simple molecular structure is a big influence in its physical properties let's go through a few of those fullerene has lower melting and boiling points than both diamond and graphite because of having a smaller structure and fullerene is method only the relative peak in the molecular forces of attraction must be broken these bonds right so it does not require as much energy as much we required for diamond and graphite now moving on they're different for the rings where the molecule contains different number of carbon atoms that's why we include the c16 name because it can be say 60 say 50 c72 c70 there are many different types however c60 is the only one we discuss in your course c60 fullerene is not as hard as diamond it does not take as much energy to break the intermolecular forces so as compared to diamond so it's not that hard c60 does fullering does not conduct electricity all carbon atoms and c60 only form three bonds the fourth electron each atom can only move around within each c60 molecule electrons cannot jump from molecule to molecule so they don't conduct electricity unlike diamond and graphite c60 pull green does dissolve in some solvents only peak relative molecular intermolecular forces are supposed to be broken which are really easy to break that's why c60 fluorine can dissolve in a few solvents that finishes this chapter thank you