Teflon = polytetrafluoroethylene (PTFE) = -(CF2-CF2)n-. Monomer = tetrafluoroethylene (CF2=CF2).

Why non-stick? The C-F bond is one of the strongest single bonds in organic chemistry (485 kJ/mol vs C-H at 413 kJ/mol). The fluorine atoms completely shield the carbon backbone, creating a smooth, low-energy surface. Nothing can chemically attack or adhere to it.

Properties: Chemically inert (resists all solvents, acids, bases — even aqua regia), very high melting point (327 degC), excellent electrical insulator, extremely low coefficient of friction, non-flammable, non-toxic.

Uses: Non-stick cookware coating, gaskets and seals in chemical plants, insulation for wiring, plumber's tape (PTFE tape), surgical implants (biocompatible), Gore-Tex fabric (stretched PTFE with micropores — waterproof but breathable).

JEE trap: Students sometimes confuse Teflon with other fluorinated materials. Remember: Teflon = PTFE = only C and F atoms in the polymer chain. Freon (CCl2F2) is a completely different compound (chlorofluorocarbon used as refrigerant — ozone depleting).