Final answer:
BF₃ (Boron trifluoride) has a central atom with sp² hybridization, unlike CH₄, SF₄, and H₂O, which have sp³ or sp³ d hybridization on their central atoms.
Step-by-step explanation:
The molecule with a central atom that does not have sp³ hybridization is BF₃ (Boron trifluoride). In BF₃, the boron atom is surrounded by three regions of electron density: the three fluorine atoms. However, it does not have a lone pair of electrons. This arrangement leads to sp² hybridization, where the molecule has a trigonal planar geometry. This is unlike CH₄ (methane), SF₄ (sulfur tetrafluoride), and H₂O (water), where the central atoms have sp³ hybridization. Methane, with four single bonds, and water, with two single bonds plus two lone pairs of electrons, both feature tetrahedral geometry around the central atom indicative of sp³ hybridization. While SF₄, according to Figure 8.18 or Figure 5.18, exhibits sp³ d hybridization, due to having one lone pair of electrons on the sulfur atom in addition to four F atoms, resulting in a trigonal bipyramid shape.