I got a C

If I get a C in a class but straight As for the rest of the semester , how terrible does it look on my college application if I’m applying to top schools

everyone has different perspectives. I do not know what schools you view as “top schools.” If you are thinking of Ivy Leagues, HYPSMC, etc., and if you are NOT talking about rescinding an offer of admission, then it will look bad.

It more depends on how you did in the past, however. For example, have you been getting straight As in the past throughout your high school except then?

Don’t forget that colleges don’t judge solely on your GPA, however.

i got mostly As and some Bs, but I figured this one C would bring me down a lot. I meant like Uchicago as Top School, and GPA is a huge factor right?

It hurts, but it’s not the end, not by a long shot. Yes GPA is important but it is NOT everything.
If it makes you feel a little more optimistic, I got a C as a sophomore but ended up getting into an Ivy. Package yourself well, and do well in your other classes so the admissions people end up thinking the C was a clerical error or something lol.

If you do end up getting a C, what will your cumulative GPA be?