There are pros and cons for choosing LAC over large Uni for science. I would take the emphasis off the big picture, and instead focus on “of the schools I am considering attending, which ones have the best science dept for me?” And Best science dept can mean different things to different people, so you set the factors to judge each one by.
Do you want to do research early on in your college years? If so, determine which schools will let you do that. At some large Universities, you may be shut out of research til your jr/sr years. Again, every school may be different, so don’t assume because one Uni does it this way, that ALL Universities do it that same way.
Does having a more personal interaction with professors (instead of TAs) matter to you? Do you like to “disappear” into a crowded lecture hall of 200 students, or do you prefer the more discussion based class of 20-25 students?
There are the basics mentioned, finding out what your path of courses is going to look like, and how often each course is taught. Have you met the professors, or checked them out on ratemyprofessor.com? In a small department, avoiding a bad professor is harder to do. At a large Uni, you might have a wider range of choices of professors.
Do you want to go to grad school? Having a closer relationship to profs at an LAC may garner better recommendation letters for grad school. Ask about where each college’s students get accepted to grad school.
Lots of choices, no one answer to which setting is right for you. Good luck!