ote: some of these materials have more than one name.
1 carbon dioxide
2 carbon monoxide
3 sulfur dioxide
4 sufur trioxide
5 nitrous oxide
6 nitric oxide
7 dinitrigen trioxide
8 nitrogen dioxide
9 dinitrogen tetroxide
10 dinitrogen pentoxode
11 phosporous trichloride
12 phosphorous pentachloride
13 ammonia
14 sulfur hexachloride
15 phosphorous pentoxide (phosporous V oxide)
16 carbon tetrachloride
17 silicon dioxide
18 carbon disulfide
19 oxygen difluoride
20 PBr2 (I've never heard of this; do you mean PBr3?)
PBr2 would be phosphorous dibromide PBr3 would be phosphorous tribromide
