(photo credit: Daniella Zalcman)

Teflon is polytetrafluoroethylene, or PTFE. The molecular structure of Teflon is based on a chain of carbon atoms, the same as all polymers. Unlike some other fluoropolymers, in Teflon this chain is completely surrounded by fluorine atoms. The bond between carbon and fluorine is very strong, and the fluorine atoms shield the vulnerable carbon chain. This unusual structure gives Teflon its unique properties. In addition to its extreme slipperiness, it is inert to almost every known chemical. (source)