1. The problem statement, all variables and given/known data What are simple molecular structures? 2. Relevant equations 3. The attempt at a solution Simple molecular structures consist of molecules containing fixed numbers of atoms joined by strong covalent bonds. I'm getting confused with all the different structures in chemistry. How simple is simple? Simple molecular structures are : water, CO2 because they are not forming long chains as in diamond. What about DNA? I think saw somewhere that DNA is a simple strucure (i may be wrong). Is it simple because the chians are a fixed size?