Learners calculate gas density from the standard molar volume and observe how the density increases with the increasing molecular weight of the gas.

Learners complete an exercise to match chemical formulas with the names of binary compounds, tertiary compounds, and ions.

Learners read the definition of atomic weight and obtain the weights of elements by viewing the Periodic Table and charts that list atomic weights by name or symbol.

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.