# Which of the following species is tetrahedral: SiCl4, SeF4, XeF4, or POCl3 ?

$\text{Silicon tetrachloride and pockle3.}$
The structures of these molecules are easily predictable by $\text{VSEPR theory}$. Pockle3 and silicon tetrachloride have 4 regions of electron density arranged about the central atom, and these element-element bonds assume tetrahedral geometry.