Students identify the parts of a triple beam balance and practice measuring the mass of objects.

Learners view an explanation of how to read a graduated cylinder by measuring the lowest portion of the meniscus. A quiz completes the activity.

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

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 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.

In this animated object, learners examine the formation of peptide bonds through dehydration synthesis.

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 object, learners examine the formation of ester bonds in the synthesis of lipids using triglyceride biosynthesis as an example. Ester bond formation is described as a dehydration synthesis reaction.

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.

The student identifies the anatomical parts of the ear and learns the purpose and function of these parts. A review follows the lesson.

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

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.

In this animated activity, learners examine the terms "half-reaction," "oxidizing agent," and "reducing agent" and follow five interactive examples to balance equations for oxidation-reduction reactions. Three problems are provided as a self-check.

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.

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 animated object, learners examine the chemistry behind table salt.

Ions are electrically charged particles obtained from an atom or from a chemically bonded group of atoms by adding or removing electrons. Eight examples illustrate the number of protons, neutrons, and electrons in positive ions (cations) and in negative ions (anions).

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 study the effect that pressure has on boiling temperatures. Once a liquid has reached a full boil, additional heat does not raise the liquid’s temperature; however, pressure can vary the boiling point of a liquid. 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.