(above) difluoromethane (CH2F2). This image is 500 x 500 pixels; the original image is 4096 x 4096 pixels.
difluoromethane CH2F2: consists of a centrally placed carbon atom with two hydrogen atoms and two fluorine atoms arranged at the points of a tetrahedron around it. It is equivalent to methane molecule with two hydrogen atoms replaced by two fluorine atoms. It is an HFC.
HFCs or Hydro Fluoro Carbons contain only carbon, hydrogen and fluorine. Hydrofluorocarbons are being adopted in preference to the related hydrocarbons that contain chlorine and fluorine (the CFCs). HFCs are still greenhouse gases but (because they do not generate reactive chlorine) they do not destroy ozone in the ozone layer.
Haloalkanes are formed when a halide atom (Fluorine, Chlorine, Bromine, or Iodine) is bonded to carbon in an alkane. An alkane is a compound made fron carbon and hydrogen (i.e. it is a hydrocarbon) with no multiple bonds (i.e. it is saturated). Examples include methane (CH4) ethane (C2H6), propane (C3H8), and butane (C4H10).