In this screencast, learners examine the kinds of physical and chemical changes that occur in substances.

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

In this animated object, students examine what happens when electrons share molecules.

Students examine atomic structure and the octet rule.

Vapor pressure is the pressure exerted by molecules in the gas phase in equilibrium with a liquid or a solid. Two examples are used to illustrate vapor pressure: the drying of clothes and the evaporation of ice.

Learners examine the meaning of oxidation, reduction, and half-reaction, and watch a film showing the deposition of copper metal from the reduction of copper (II) ion by aluminum. A brief quiz completes the activity.

Learners examine phase diagrams that show the phases of solid, liquid, and gas as well as the triple point and critical point.

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

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.

Learners view several movie clips that demonstrate the use of an indicator to follow the neutralization reaction that occurs when an acid and a base are mixed. Students test their knowledge in a series of questions. Immediate feedback is given.

Learners read about lab equipment and basic safety measures. In a quiz, they view photos and determine if the lab technicians pictured are using safe practices.

In this interactive object, learners calculate the amount of heat evolved or absorbed in chemical reactions. Four practice problems are provided.

In this animated object, students are introduced to moles as a measurement.

In this interactive and animated object, learners use solubility rules to predict when an insoluble ionic compound will precipitate in a double replacement reaction. Step-by-step examples are given.

Viewers watch an introduction to monosaccharides, disaccharides, and polysaccharides. The processes for dehydration synthesis and hydrolysis.

Learners examine the method for calculating the atomic weight of copper from the natural percent composition of each of its two isotopes.

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.

Roman numerals are used to identify the charges on metal cations having multiple oxidation states. Five examples are provided for practice.

In this animated object, learners examine how gas volume varies directly with absolute temperature (K at constant pressure). An example of a sample of gas at two conditions of volume and temperature is used to illustrate the law.

In this animated and interactive object, learners examine the properties of liquids, solids, and gases.

Learners read definitions of atomic symbols, atomic numbers, and mass numbers and then answer questions about the number of neutrons, protons, and electrons in select elements.

In this animated and interactive object, learners follow two rules to write unit conversion fractions.

Learners examine graphs and read that the heat of fusion is the heat energy absorbed by one mole of solid as it is converted to liquid, while the heat of vaporization is the heat energy absorbed by one mole of liquid as it is converted to gas.

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

Learners identify combination, decomposition, displacement, and combustion types of redox reactions. They also watch a video clip that demonstrates the reaction of sodium and water.