In this interactive object, learners calculate formula and molecular weights by working through five examples and two problems.

In this interactive and animated object, students distribute the valence electrons in simple covalent molecules with one central atom. Six rules are followed to show the bonding and nonbonding electrons in Lewis dot structures. The process is well illustrated with eight worked examples and two interactive practice problems.

In this well-illustrated object, learners examine the structures and properties of the four types of solids: molecular, metallic, ionic, and covalent network. Five interactive questions are provided.

Learners assign oxidation numbers to atoms in neutral compounds and in polyatomic ions. Six examples are worked through in detail, and three problems are provided.