Match these items.
phosgene
1. a halogenated gas that may damage the ozone layer
2. world war i poison gas
benzene
3. a typical reaction of alkenes
addition
4. insecticide
freon
5. aromatic molecule
ddt

Here's what I get  

Explanation:

the number of valence electrons for each molecule or ion is shown beneath the structure. remember hydrogen will not have more than two electrons. this hydrogen is part of a covalent bond (sharing two electrons). a double bond here would cause hydrogen to share four electrons with phosphorus.