How bad will a C+ look on my transcript?

I’m a rising senior at a tough prep school in Ohio, and it looks like I may get a C+ in Algebra II or Honors Chem based on how I did on final exams. I do not know yet, but how bad is this? I have a 3.6 GPA, scored a 30 on the ACT, (I am retaking it), and am involved in a lot of extracurriculars. This would be my first grade lower than a B in high school. I am looking at schools like Ohio State, Georgia Tech, and UC Davis. Would a C+ or two scare them away? Thanks in advance.

I too wanna know.

A C+ or two, no. If it brings your GPA down too much, yes. Look up the Common Data Set for colleges in which you are interested, section C. And see if your school uses Naviance.