For POLS course The chemical bonds and reactions section has five videos and two text files.  Take notes on these as your pre-class assignment.

For POLS course The electron shells and orbitals section has three videos and one text file. Take notes on these as your pre-class assignment.

For POLS course The elements and atoms section has four links: two are videos and two are text files.  Take notes on these as your pre-class assignment.