Diamond, graphite and graphene are forms of carbon with different giant covalent structures. Metals and alloys - AQA The structure of metals explains their high melting and boiling points and ...

It melts at 3727 C. The stable form of carbon at room temperature is Graphite which has a hexagonal crystal structure. (Top diagram) Diamond is metastable at room temperature and has a diamond cubic ...

By extracting carbon-14 from the graphite, the radioactivity decreases ... radioactive carbon-14 is securely encased within the diamond structure, ensuring safety for humans and the environment.