no
No, carbon is not a heterogeneous mixture. It is not a mixture because it is an element. The term heterogeneous can only be applied to mixtures.
Pencil lead is actually not lead (Pb) at all, but it is graphite. And graphite is simply carbons atoms. So, no, it is NOT a compound mixture.
carbon is an element
Heterogeneous
Graphite is a form of pure carbon; it does not contain gold.
No, graphite is a pure substance. It is a form of the pure element carbon.
It is heterogeneous mixture because the carbon dioxide is not completely dissolved, and easily spotted.
Graphite is an element. It is composed entirely of carbon atoms arranged in a specific crystalline structure.
No, carbon mixed with sand is not a homogeneous mixture. It would be considered a heterogeneous mixture because the carbon and sand do not completely mix at a molecular level and can be visibly distinguished from each other.
Graphite is a pure substance and a crystalline form of carbon. It is not a mixture since it is composed of only one type of atom, carbon. Additionally, graphite is not a metallic element, it is a non-metal.
No, a diamond is a form of Carbon which is an element.
It is a compound.