the good thing about bsci is that you can try out a bunch of classes before deciding. so first year u can take bio, chem and phys classes, then decide which ones u want to major in future years. bsci is a generalistdegree tho, for those majors it's usually a good idea to at least do a honours year or masters for more job opps - a lot of the chem and bio jobs like for you to have research exp, so honours can help u apply for your first job, or you can get some internship experience/get lucky otherwise. some jobs (usually the consulting ones) don't mind if u only have a bachelors though. phys is a bit more tricky to find jobs in physics with only a bachelors, u can pivot into some other industries though like data and software. otherwise you'll usually need to study further to specialise a bit more, there are some good options like medical physics (a bit competitive to get a placement tho, i was interested in it but you have to be willing to move around to get a placement to become accredited), chem related stuff like condensed matter and materials science, quantum tech etc