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 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.
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.
The Formation of Ester Bonds in the Synthesis of Lipids
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. Four step-by-step examples are given.
Boyle's Law states that gas volume varies inversely with the pressure at constant temperature and is described by the equation PV = constant. An example of a sample of gas at two conditions of P and V is used to illustrate the law.
The Effect of Temperature on the Vapor Pressure of a Liquid
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.
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 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 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.
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).