system
Given the following post, respond as if you're commenting on Reddit:
human
Is ironoxide soluble in water?

If so, what is it that makes it soluble? If not, what is the that makes it nonsoluble?
I looked at the difference in electronegativity between iron and oxide and figured it was polar. Since water also is polar I thought it would be soluble in water, but when I later on was looking at ironoxide on wikipedia it said it was nonsouble in water. I'm pretty bad at chemistry, would be great if someone could explain.
gpt
When a material dissolves in water, three main things must happen.  First, the material must be broken up into its consitutent ions or molecules.  Second, water has to spread apart to make room for the individual pieces in solution.  Third, the individual pieces must be surrounded by water (solvated).  

It always is unfavorable to break a solid up into pieces because those interactions were doing a good job holding the solid together.  It is also always unfavorable to spread water apart because water molecules are strongly attracted to other water molecules.  The solvation process that occurs after this is always favorable because new attractive solvent-solute interactions are forming.  Whether or not something is soluble is dependent mainly on how unfavorable the first step is compared to how favorable the third step is (the second step is pretty much the same all the time).

For iron oxide, the bonds holding together the solid are very strong.  In solution, iron oxide exists as hydrated iron hydroxide, a neutral species that is capable of forming extremely favorable bonds with water.  Unfortunately, those interactions are not as strong as those that iron hydroxide can form with itself, and it does not dissolve in water to any significant extent.