[une_fille_radicale]

Hi everyone.
I'm doing a lab on density, and I'm a bit confused. The objective statement of the lab that was given to us is as follows: "To understand the concept of density and its applications; to review the techniques of graphing and the interpretation of graphs."
I was confused about what kind of a hypothesis I can make based on this, but finally I decided to predict which compound (ethylene glycol, 1-butanol or water) will be the most dense.

However, I really have NO idea how do predict this without any information on the compound other than its chemical formula.
What I'm thinking is this: since the formula of 1-butanol contains the most atoms, it will likely be the most dense of the three compounds. Ethylene glycol has the second largest number of atoms, it will be second in order of density, and water will accordingly be the least dense compound.
However, I really...I have no idea if that even makes sense. Could someone give me any feedback on this hypothesis? Is there another factor that I can use to predict which compound will be the most dense? Should I mention the fact that 1-butanol also has the heaviest atoms, does that have any relation to it or would it be compensated for with an increase in size? :/

I'm really sorry to be asking such a silly question Have a nice day! Thank-you for any *delete me*

[Arkcon]

The hypothesis you suggested isn't a bad one.  What did you observe?  Or, when you perform the experiment, check if the observations match your hypothesis.  If they don't try to to see if you can amend your hypothesis  -- what other things can be contributing to density.

[une_fille_radicale]

I found that ethylene glycol was the most dense, water the second and 1-butanol was the least dense. I have no idea how to explain THAT
I know that the only other thing is the volume (since D=m/v), which I wouldn't know from the chemical formula...Is there something I'm just not thinking of? :/
Thank you, at the moment it looks like I'll be sticking to this hypothesis.

[fledarmus]

The number of atoms in a molecule is certainly one criteria that would affect density. But what do you know about the forces between the molecules? The stronger the forces between the molecules, the closer together the molecules would be, and the more dense the liquid would be. What sorts of intermolecular forces would you be looking at for these three compounds?