Book 27, Question 10
How can diamond and pencil graphite both be made of carbon?
Diamond and graphite are made of the same atoms, carbon, but arranged differently.
In diamond, each carbon atom is locked to four neighbors in a strong 3D lattice, making it the hardest natural material. In graphite, carbon atoms form flat sheets that slide over each other, so it is soft and slippery. The same atoms can act very differently when their pattern changes.