Answer
a) $CO$.
b) $S_{2}F_{4}$
c) $Cl_{2}O$
d) $PF_{5}$
e) $BBr_{3}$
f) $P_{2}S_{5}$
Work Step by Step
Since all of the compounds are contently bonded (i.e. covalent compounds), we must name them using the appropriate prefixes. The first element name stays exactly the same and before the second compound, the appropriate prefix is added and the suffix for these compounds is "ide".
a) $CO$. Since the prefix is mono, it means there is one oxygen.
b) $S_{2}F_{4}$ Since the prefix is "di" for sulfur, it means there are two sulfurs and since the prefix is tetra for fluorine, it means there are 4 fluorines.
c) $Cl_{2}O$ Since the prefix is "di" for chlorine, it means there is two chlorine and since the prefix is mono for oxygen, it means there is one oxygen.
d) $PF_{5}$ Since there is no prefix for phosphorous, it means there is only one phosphorous and since the prefix is penta for fluorine, it means there are 5 fluorines.
e) $BBr_{3}$ Since there is no prefix for boron, it means there is only one boron and since the prefix is "tri" for bromine, it means there are 3 bromine.
f) $P_{2}S_{5}$ Since the prefix is "di" for phosphorous, it means there is two phosphorous and since the prefix is penta for sulfur, it means there is 5 sulfurs.
