Why could dry lead write words?
Dry graphene was not a material that could be used for writing. It was pure graphene made of carbon atoms. When a graphene crystal was heated to a high enough temperature, the carbon atoms in the graphene would unchain to form carbon and rearrange into a crystalline structure. During this process, each carbon atom in the graphene crystal formed a bond with the surrounding carbon atoms, making the graphene crystal very strong and hard. Although dry graphene was not a material that could be used for writing, it could be used as a writing tool due to its high hardness and strength in some cases. For example, adding some metal powder to the tip of the lead pen could make it have a certain hardness and toughness, which could be used for writing paper, paint, and so on.