CARBON (OCCURENCE AND PROPERTIES)
Carbon naturally occur in two main crystalline allotropic forms, carbon-graphite and carbon-diamond
|
Carbon-diamond |
Carbon-graphite |
|
Shiny crystalline solid |
Black/dull crystalline solid |
|
Has a very high melting/boiling point because it has a very closely packed giant tetrahedral structure joined by strong covalent bonds |
Has a high melting/boiling point because it has a very closely packed giant hexagonal planar structure joined by strong covalent bonds |
|
Has very high density(Hardest known natural substance) |
Soft |
|
Abrassive |
Slippery |
|
Poor electrical conductor because it has no free delocalized electrons |
Good electrical conductor because it has free 4th valency delocalized electrons |
|
Is used in making Jewels, drilling and cutting metals |
Used in making Lead-pencils,electrodes in batteries and as a lubricant |
|
Has giant tetrahedral structure |
Has giant hexagonal planar structure |
1. What are allotropes?
2. Name crystalline forms of carbon?
3. What are the differences between the two allotropes?