Learners examine a table of common polyatomic ions. Eight examples are provided for practice.

Learners convert units used to designate pressure. Units for pressure are atm, mm Hg, torr, and pascal.

Students read brief descriptions of atoms, molecules, elements, and compounds, and complete a matching exercise that pictures these particles and molecules as pieces of taffy.

In this animated and interactive object, learners observe how two, three, or four groups of electrons around the central atom cause the shape of the molecule to be linear, trigonal planar, bent, tetrahedral, or pyramidal. Seven examples and eight interactive questions are provided.