Learners view an animated presentation showing how the pH level of a cleaning solution is controlled in a closed-loop system in a manufacturing setting. A quiz completes the activity.

Learners examine how the boiling point increases with increasing pressure. An example from industry is given.

Learners view illustrations showing the direct dependence of the volume of a gas on temperature and consider the relationship between the Kelvin and Celsius temperature scales.

Chytrids, as members of this group are known, are found everywhere. In this animated learning object, students examine the role of chytrids and their impact on the environment.

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

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

Learners examine the periodic table to identify metallic elements that have either fixed or variable oxidation states.

Learners examine how chemists use moles to "count" atoms by weight. Examples are given.

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

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

Students examine standard pressure in this interactive object.

Learners observe that the melting of a solid and the freezing of its liquid occur at the same temperature. The melting point is an intrinsic property and is used to identify a substance.

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

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.

Learners examine the lifecycle of basidiomycetes. Terminology and fungi examples are provided.

This learning object demonstrates the process by which antigens are identified, processed, and presented to mediators of the cellular immune system.

In this animated object, students examine the role equilibrium plays in everyday life. Formulas are presented in an interactive way.

Students read different definitions of "acids" and "bases." In an interactive exercise, they identify if a substance is an acid or a base.

In this animated object, learners examine the major descending tracts of the nervous system. A matching exercise completes the activity.

In this interactive object, students examine a type of chemical bond known as the "hydrogen bond."

In this animated and interactive object, learners examine kinetic and potential energy as well as the first law of thermodynamics and the flow of energy between a system and its surroundings. Students also answer questions about exothermic and endothermic reactions

Learners observe that the volume of one mole of any gas is 22.4 L at standard temperature and pressure. An illustration shows that only the mass of the molar volume differs with the identity of the gas.

In this interactive and animated object, learners examine the characteristics, ecological importance, and lifecycle of the ascomycetes of the fungi kingdom.

Learners review a graphic summary of the three series of reactions that occur during cellular respiration and the net energy (ATP) yield of that process.