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.

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

Students review the positions of metals, metalloids, and nonmetals in the Periodic Table and the general characteristics of each. A quiz completes the object.

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 peptide bonds through dehydration synthesis.

Students read an introduction to the lab equipment used to contain and dispense chemicals. A quiz completes the activity.

Learners read a brief introduction to monosaccharides, disaccharides, and polysaccharides. The processes for dehydration synthesis and hydrolysis are shown.

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

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.

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

Learners examine how melting, vaporization, and sublimation require energy input while freezing and condensation release energy.

Students solve a molarity problem in a drag and drop exercise.

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

In this animated and interactive object, learners observe how two, three, or four groups of electrons around the central atom cause the shape of the molecule to be linear, trigonal planar, bent, tetrahedral, or pyramidal. Seven examples and eight interactive questions are provided.

Students examine atomic structure and the octet rule.

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

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

In this interactive object, students examine how the volume and temperature of an ideal gas relate under conditions of constant pressure and quantity.

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

Students read about the basic organization and structure of the periodic table of elements. By clicking on the symbol, they can read that element's atomic number and weight. In an exercise, students identify elements as belonging to a group, a period, or neither.

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 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 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.

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