Is chemistry a high-scoring subject? (of course after I've done my best in preparation)

Selecting International Relations with International Law is a good choice? or Int. Law with Political Science goes well?
..and yes! somebody kindly confirm that is it allowed to select IR with IL???

I do have a geography background, so would it be fine to select it or should I go for Psychology (as I've heard its easy to prepare, even without a prior knowledge)

Hoping for a quick response