Why is graphite soft and easily broken? The bonding between graphene layers is very weak allowing them to slide over each other. For example, when you use a pencil, the sheets of carbon are rubbed off onto the paper.
Why does diamond have a higher melting point (approx. 4027 ℃) than graphite (approx. 3600 ℃)? Each carbon atom within the structure of diamond has four covalent bonds that require breaking rather than the three each in graphite.