Just review basics: proton, electron, neutron, atomic mass/number, ionic and covalent bonds (polar/nonpolar) , balancing equations, gas laws (Boyle, Charles, Dalton, etc). There are a bunch of chem questions on the tests, but they just cover basics.
Which college are you applying for? I have scored 89% (99%percentile - not sure how accurate the percentile is) and my college only takes the top 72 applicants based on the TEAS scores. I am so nervous!