# What is the molecular geometry of PBr5? Draw its VSEPR and Lewis structure.

$P B {r}_{5}$'s molecular geometry is trigonal bipyramidal.
Let's start with its Lewis structure. $P$ has 5 valence electrons and $B r$ has 7 valence electrons, which means that a total of $5 + 5 \cdot 7 = 40$ electrons must be accounted for.
$P$'s bonds with the five $B r$ atoms account for $5 \cdot 2 = 10$ electrons, while the three lone pairs on each $B r$ atom complete the rest of the electrons - $5 \cdot 6 = 30$ electrons.
SInce $P$ forms bonds with 5 other atoms and has no lone pairs, it has a steric number and a coordination number equal to 5 . According to VSEPR Theory, this corresponds to a trigonal bipyramidal molecular geometry.