In this animated lesson, learners read about the disulfide bond, the second strongest chemical bond in the hair. This bond can only be altered by chemicals.

Students read an explanation of chemical formulas in this animated activity. A quiz completes the object.

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

In this interactive object, learners determine the limiting reagent and the excess reagent in chemical reactions. Learners test their knowledge by solving three problems.

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

In this animated object, learners examine the chemistry behind table salt.

Learners examine the meaning of theoretical yield, actual yield, and percent yield. They test their knowledge by solving two problems.

In this animated object, learners examine how changes in pH affect the salt bonds in strands of hair.

In this well-illustrated activity, learners examine the three types of intermolecular forces: dipole-dipole forces, London or Van der Waals forces, and the hydrogen bond. Two interactive questions are included.

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

In this screencast, learners examine the properties of the hydrogen bond and how the bond changes when hair is shampooed or styled.

Learners use the coefficients in a balanced equation to develop the mole ratios of reactants and products involved in the reaction. Five interactive examples illustrate the method, and students test their knowledge by working four problems.

In this animated object, learners examine synthesis, decomposition, exchange, and reversible reactions.

In this learning activity you'll review the six different ways in which electricity is produced: chemical, friction, heat, light, magnetism, and pressure.

In this animated object, learners examine how the heating or cooling steps in a manufacturing process work to control a chemical reaction.

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

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.

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

In this interactive lesson, students examine the quantitative relationship between chemicals in a balanced mathematical equation.

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.