Usually with some degreaser for grease pencil. For regular pencil try an eraser.
Colored Wax
Pencil lead is a mixture of graphite (or other colored pigment) and a binder (e.g. clay, wax, plastic, grease).
Sandpaper.
lead pencil
No, he preferred Crayola markers (especially the purple).
The chemical symbol for a pencil is typically "C" for carbon, as the core of a pencil is made of graphite, a form of carbon.
It allows you to mark on glass to label something during a lab and then later wash off the grease.
Crayons, pencils, markers?
You're thinking of carbon. Both pencil lead and diamonds are allotropes of carbon.
A diamond and a pencil lead (graphite) are both made of carbon. The difference is the crystalline structure of the carbon atoms.
The "lead" of a pencil is made from graphite, which is a form of carbon.
It is a case for containing your school material, like rubber, pencils, ruler, markers.