Resources:

UK source on Period 3 oxides: http://www.chemguide.co.uk/inorganic/period3/oxidesphys.html
(It contradicts the text because it states that SiO2 won't conduct electricity as a liquid--molten state--or a solid...bottom of p. 120 in text says molten SiO2 has freely moving electrons...molten form/structure of giant, network covalent structures is not well-established.)

More on SiO2 and carbon allotrope properties:
http://www.docbrown.info/page04/4_72bond4.htm (Seems fairly reputable but not specific to IB...UK Advanced Level represented)
http://www.patana.ac.th/parents/curriculum/chemistry/units/LR404.html (Not sure how reputable...British International School in Bangkok?)

Interactive Learning:
http://ibchem.com/IB16/05.00t.htm

Bitesize learning summary of periodicity of halogens + go to the next page and do a simple simulation of halogen displacement reactions:
(Click the yellow "start" button to start, then click the rubber bulb part of each eye dropper, then click the "next" button to complete the simulation.)
http://www.bbc.co.uk/schools/gcsebitesize/science/edexcel_pre_2011/patterns/groupsrev4.shtml

Video Resources:
http://www.msjchem.com/topic-3-periodicity.html

https://www.youtube.com/playlist?list=PL816Qsrt2Os3hxutLsNl8m2V8mdmAQTFs

Practice Tests:
http://masseychem.weebly.com/ib-review-answer-keys.html

https://sites.google.com/a/nisbah.com/chemistry/IBDP-Chemistry/dp-chemistry