If you want to major in Chemistry, thenI would say to take it.
If you do well, then you will know chemistry is a feasible option.
If you don’t, then, well, it isn’t.
Read this and follow the advice to do well:
http://talk.collegeconfidential.com/high-school-life/2026961-what-to-do-when-you-arent-doing-well-in-a-hs-class-p1.html