Just going for physics and working as a teacher wont work. You will still need a student teaching course and additional education coursework usually at a masters degree level- thus, you could consider a dual major or doing the physics minor and majoring in elementary education (which would be the best route- you could then be endorsed in physics at the 6-12 level and have a license in elementary education allowing you to work K-5/6 and also 6-12 as a physics teacher).
You could also consider taking physics as your major, then going after a masters of arts in teaching- most teacher jobs want to see the masters degree in this economy anyways.
Those are your options.