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Description
Flashcards by fahimarehman04, updated more than 1 year ago
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Created by fahimarehman04
over 11 years ago
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| Question | Answer |
| What are allotropes? | Different structures of the same element for example diamond, graphite and fullerenes. |
| What are fullerenes? | Carbon structures that form spheres that can be used to carry and deliver drug molecules around the body and to trap dangerous substances in the body and remove them. |
| Why are diamond and graphite useful? | They are both giant covenant structures of carbon atoms. Diamond is the hardest natural substance known and have a very high melting and boiling point. The imperfections that naturally occur in diamonds from cleaving plates allows them to be shaped. This then makes them useful for to be used in cutting tools and as jewellery. Graphite has a high melting and boiling point but the layers can slide over each other, making them useful for it to be used in pencils. |
| What are the properties of diamond? | Giant covenant bonding involves electron sharing. Every carbon atom in diamond is covelently bonded four other in a three dimensional tetrahedral lattice with all the outer shell electrons being shared. Strong covenant bonds in all directions makes the diamond hard. Large amount of energy is then needed to break the bond giving it a high melting bond. An abscenece of free electrons, meaning diamond does not conduct electricity. |
| What are the properties of graphite? | Every carbon atom in graphite is covalently bonded to three others in flat hexagonal layers. This leaves an unshared outer shell electron. The separate layers are only weakly attracted. The strong covalent bonds gives graphite a high melting point. The delocalised electrons makes it a good electrical conductor. |
| What can nanotubes be used for? | In the catalyst system, atoms of the catalyst can be attracted to the large surface area. |
| Give some information on giant molecular structures: | Any compound with this structure will have high melting point. If bonds are formed in different directions then then the substance is hard. If there are no free electrons the substance will not conduct electricity. |
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