How to prepare for my physics and chem pre board ?

Ok people so I have my pre board 2 from 3rd Jan and on 5 Jan my chem pb is there the thing is in chem biomolecules is half left and in physics alternating current and wave optics is left today I will complete physics syllabus but man how do I revise physics like Its been some time since I touched modern physics tell me and how do I manage chem? I am not scared of maths as there 5 days of gap and my maths syllabus is almost done only definite integrals and 3d remains but man along with this I need to complete my practical files on the day of pb-2 I need to submit phy-chem practical files