CF4, or tetrafluoromethane, is a tetrahedral molecule. As indicated by the "tetra" portion of the name, the molecule has four groups of electrons bonded around a central atom.
As with many electron bonds, there are several parts to a tetrahedral molecule. The main part of the molecule is the atom, which always lies in the center. The four groups of electrons are spaced around the atom. These electrons are never in lone pairs, and they always stay together in an even pattern around the atom, although they are not always equal distances from each other.
Because electrons are more attracted to fluorine than they are to carbon, the electrons spend more time closer to the fluorine in the CF4 model. The electrons are held together with covalent bonds, and these bonds pull toward the fluorine and pull away from the carbon. Although the fluorine and the carbon are somewhat equal, the fluorine has a stronger pull. The chemical formula CF4 reflects the greater pull of the electrons to the fluorine. The lack of a number with the carbon indicates the electrons are not pulled toward the carbon but are instead pushed away from it.