Graphene

Why cant you make graphene a little thinner then it is?

Becuase graphene is literally one layer (which in this case is one atom), thick. Atoms are tiny, they're the smallest thing you can make a material out of.

oh if there was more than one layer what would the substance we called?

If there were layers (each one atom thick) of carbon, but they are not chemically bonded, they would just be called layers of graphene, even if they were right next to each other with little to no space in between them. If you're doing the GCSE spec, which I'm suspecting, then the only other two structures you should know that carbon forms are diamonds and fullerenes. Diamonds has multiple layers of carbon (this is just as far I can see in the image below, this isn't confirmed in the spec and you don't need to know that, it just mentions that diamonds have 'giant covalent structures', which you do need to know). Fullerenes are just hollow spheres of carbon (you do need to know this for the GCSE spec).

Fullerenes:


Diamond:


Layers of graphene:

Diamonds has multiple layers of carbon

Diamond does not form layers.

Layers of graphene is essentially just graphite.