For the Caltech application, you have to write about 3 activities/experiences that inspired your passion for STEM. I was wondering if it would be better to write about 3 experiences that focus on one particular science field or 3 experience that talk about my inspiration for math and several fields of science (spread out).
I think you should write about whatever sincerely inspired your passion for STEM. It is okay to be spread out - they don’t expect 17 year olds to have their lives planned out, even at Caltech.