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.

This lesson gives the student an overview of grinding wheels and pedestal grinder procedures.

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

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

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.

This animated lesson demonstrates hydraulic pressure switch applications when the switch is connected to a ladder circuit to operate in a hydraulic system.

This animated lesson shows several ways that a hydraulic pressure switch, connected in a ladder circuit, causes the cylinder of a hydraulic circuit to perform various applications.

This animated lesson shows the operation of timer-on and timer-off delay relays used in ladder circuit operate.

Equilibrium plays a vital role in our lives. We'll show you how the equilibrium formula works in real life using our friend the chicken.

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.

At the end of this lesson you will be able to

- Explain what biosecurity means.

- Describe why biosecurity is important.

- Identify what kinds of disease agents we try to prevent or control with biosecurity.

- Demonstrate disease agent-host-environmental interactions that result in disease.

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

In this animated object, learners view hydrogen and hydroxide ions in a solution. A brief quiz on the basic principles of the term pH completes the activity.

In this interactive object, learners examine how to properly dilute hydrochloric acid.

Learners view movie clips to determine the solubility of two ionic compounds. They also examine a solubility chart and predict the solubility of compounds.

Learners examine a table containing the names of common cations and anions.

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.

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

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

Learners calculate gas density from the standard molar volume and observe how the density increases with the increasing molecular weight of the gas.