עמוד:9

Enrichment Graphene Did you know that sometimes , when drawing a line with a simple pencil , you are actually creating some of the most advanced and expensive materials in the world ? The lead in your pencil is made of graphite , which is one of the forms of the element carbon . The structure of the graphite consists of flat layers of carbon atoms arranged one on top of the other . When we draw a line with a pencil , a layer sometimes forms on the paper consisting of only a single layer of carbon atoms . This is known as graphene . Scientists have tried for years to separate graphene from graphite . They scraped the graphene and peeled layers from it in an attempt to obtain the thinnest layer of all – only one carbon atom thick . Andre Giem and Konstantin Novoselov succeeded in creating a single layer of graphene out of graphite shavings , to which they applied adhesive tape . On this layer they managed to conduct various electrical experiments . In 2010 these two scientists were awarded the Nobel prize in physics for this achievement . Graphene has a unique combination of properties : it is transparent , flexible , very thin and very strong , it is a very good conductor of electricity and of heat . Graphene sheets can be made in a variety of sizes and shapes . Graphene is transparent and it conducts electricity . Thanks to this combination of properties , graphene is suitable for use in various innovative technologies . For example : Graphene could be used in solar cells that produce electricity from sunlight . Since graphene is thin and flexible , solar panels made with it can be used to coat surfaces with various contours . Graphene is able to serve as a coating for touch screens to make thin , transparent video screens .

מטח : המרכז לטכנולוגיה חינוכית


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