If atoms are so small that we can see them, how do they make models of them if we cant see them to see if the models are correct?

Using a microscope that magnifies your view

Ok so lecture time: Hoping this helps :)
Back when the first model was made scientists were philosophers (they thought about it... no experiments) so they made up a theory which is still being researched as of now. Over time scientists such as John Dalton, J.J Thomson, Ernest Rutherford, Neils Bohr and much more have made experiments using microscopes and other instruments that have much greater zoom. They have been bettering the models by doing experiment on the atoms.
The point of this is that they used instruments with a lot of zoom to look at the atoms themselves.

Self-ionizes to form an equilibruium system in which [ h_{3} o^{+} ]=[ oh^{-} ]=10^{-7} m