Review

recall the symbols, names and positions in the Periodic Table of some common elements, especially the first 20.
recall the various subatomic particles and their effects on the properties of an atom, such as mass and chemical reactivity.
balance simple chemical equations
recall the charges on some common ions
calculate molar masses, molar concentrations, % compostion from basic atomic mass and formula data.
identify and distinguish a range of classes of chemical reaction, particularly acid-base and redox reactions
recall properties, such as the state and solubility, of common compounds
describe the electronic structure of an atom using the s/p/d electronic sub-shell notation

As well, you should have

found your own way around the ChemCAL Online system
worked out the way the various task styles work and tried out some Hints, Explanations and Show Me buttons - even if you didn't really have to!