Atomic weights are used to convert the mass of a sample into the number of moles of the element in the sample and vice versa. Four examples are provided for practice.

In this interactive object, learners identify charges on ions, write new formulas based on charge, and balance equations using coefficients.

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

Learners examine how vapor pressure is calculated. The vapor pressure of a liquid increases with increasing temperature. If the heat of vaporization and the vapor pressure at one temperature are known, the vapor pressure at a second temperature can be calculated.