`CCl_2F_2` , known as chlorofluoromethane, has a total of 12 unshared pairs of electrons. There are three on each of the two chlorines and three on each of the two fluorines. Carbon, which has four valence electrons, is the central atom. It achieves a complete octet by forming four covalent bonds, one to each chlorine atom and one to each fluorine atom. It has no lone pairs since its four electrons are all being shared. Chlorine and fluorine each have seven valence electrons. By sharing one with the carbon atom they each end up with a complete octet, one shared pair and three unshared. I've attached an image showing how the 32 valance electrons are arranged in the Lewis dot structure of this compound.