Final answer:
SF4, or sulfur tetrafluoride, is not likely to have a tetrahedral shape due to its trigonal bipyramidal electron-pair geometry and seesaw molecular structure, which is the result of one lone pair of electrons on the sulfur atom.
Step-by-step explanation:
The molecule that is not likely to have a tetrahedral shape is SF4 (sulfur tetrafluoride). This compound has a trigonal bipyramidal electron-pair geometry and a seesaw molecular structure. The reason SF4 does not have a tetrahedral shape is due to the presence of one lone pair of electrons on the sulfur atom, which distorts the geometry from a perfect tetrahedron.
Other compounds listed like NF4+, BF4−, BeCl42−, SiBr4, and AlCl4− all have shapes that are essentially tetrahedral because they have four bonded atoms with no lone pairs on the central atom, leading to the tetrahedral molecular structure.