Sorry for posting so many DAT questions, but hopefully the discussions are helping those of us who need it!! Anyways, here it goes: The formula of the compound formed by elements Al and S is most likely: A. Al3S2 B. AlS C. Al2S3 D. Al3S2 E. None of these The key says 'C'. I've done these types of problems before (mostly involving halogens) but is there an easy way to do this? Any chem tricks I should be aware of?? PS I took a full length topscore today and got 22 PAT/19 Ac. I am STRESSED about my sceinces and math! I got so many random invertabrate questions today!! Who the heck cares about a trematoda, rotifers, and snails!!!