What is the hybridization and geometry around carbon atoms in graphene? Explain why graphene is an excellent conductor of electricity.

Video transcript

All right. Hi everyone. So this question is asking us which carbon allotrope is sp two hybridized one atom thick and an exceptional conductor of electricity. Option. A says diamond option B says graphene option C says carbonate and option D says graphite. Now recall first and foremost that the term allotrope refers to different physical forms that an element can have, right. So of the four answer choices listed, I can actually go ahead and eliminate carbonate because carbonate is a compound that contains carbon but it is not an allotrope of carbon. Whereas diamond, graphene and graphite are all carbon allotropes because they are solely comprised of carbon atoms. So when we consider each allotrope listed, all of them have their carbon atoms arranged in different ways, which is what changes the properties of each one, right. Starting off with diamond, recall that diamonds are known to be the hardest material on earth, right? And the reason for this can be attributed in part to their structure, right, because in this case, each carbon atom is covalent bonded to four other carbon atoms. And this results in a tetrahedral structure and you can expand this network even further to create a very large network of covalent bonds arranged in this tetrahedron configuration right now, because each carbon atom is bonded to for other atoms, each carbon is actually going to be sp three hybridized, which explains their tetrahedral geometry. No, the tetrahedral geometry is maintained by the fact that electrons are being held very tightly in these covalent bonds between carbon atoms. And additionally, there are no free electrons in diamonds as a result of this. Therefore, diamond does not actually conduct electricity though it does insulate very well. So diamond is sp three hybridized, not sp two, it is not a conductive electricity and it is not going to be one atom thick. So I'm actually going to go ahead and eliminate diamond as well because that cannot be our answer. So now I'm actually going to move this drawing off to the side a bit. So I can talk about graphene, right, recall that graphene has a very similar structure to only one layer of graphite because a graph sheet is composed of carbon atoms that are covalent bound together in these hexagonal rinks. Right. So here these ex exactly rings sort of combined together to create these larger structures almost like a honeycomb pattern. So if we consider the structure of graphene right, each carbon atom is bound to three other atoms, which means that graphene is in fact going to be sp two hybridized, meaning that its centers are going to be trigonal planar now graphene is actually a monolayer in the sense that it is only composed or rather it is only going to be one atom thick. So graphene is composed of the single layer of this honeycomb lattice that's been described here. So therefore, graphene is going to be the answer to this question because the pi electrons of graphene present because of the sp two hybridization provides de localization of electrons that are characteristic of conductors. And graphite graphite is very similar in structure to graphene, except that graphite is composed of multiple layers, multiple layers of graphene like sheets. So these individual sheets are going to stack up against each other and they're held together via dispersion forces. Now because these layers are being held together by relatively weak intermolecular forces. The layers are able to move past one another relatively easily making them or making graphite overall relatively soft. So our in sir is going to be option B in the multiple choice which is graphy. And with that being said, thank you so very much for watching. And I hope you found this helpful.