Should I retake my SAT subject tests?

I recently got my SAT subject test scores back. I got an 800 on math II and did pretty well on biology and got a 730. My chemistry score was a little lower though at 680. Would this score be likely to hurt me in the admissions process? I could take it again, but I’m unsure if I could really do much better because although I take chemistry, my school offers IB chemistry, not AP, and the IB curriculum for chemistry does not match well with the subject test. Would it be worth my while to give the test a second try?

No, do not take it again. First of all, you only have to send scores from one science subject test, and besides that, if you were to send both, MIT would only consider the higher score.