F2

F2, F.II or similar may refer to:

==Science and mathematics== F2, the chemical formula for fluorine \mathbb F_2 or GF(2), in mathematics, the Galois field of two elements F2, a category in the Fujita scale of tornado intensity F2 hybrid, a type of crossing in classical genetics F2 layer, a stratum of the Earth's ionosphere F-2 mycotoxin or zearalenone, a chemical produced by fungi NIST-F2, an atomic clock