The molecular geometry of the BF4 ion is tetrahedral.
This can be explained by considering the arrangement of the electron pairs around the boron atom. In the BF4 ion, boron is the central atom and is bonded to four fluorine atoms. Since boron has three valence electrons and forms four bonds with fluorine, it does not have a lone pair of electrons. As a result, the four bonding pairs of electrons repel each other equally, leading to a symmetrical arrangement.
The tetrahedral shape is characterized by bond angles of approximately 109.5 degrees between the fluorine atoms. This geometry minimizes the repulsion between the electron pairs, enabling a stable configuration for the BF4 ion.