Learners identify combination, decomposition, displacement, and combustion types of redox reactions. They also watch a video clip that demonstrates the reaction of sodium and water.

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.

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 method used to calculate the mass percent of an element in a compound. Three examples and one problem illustrate the method.

Students read a step-by-step approach on how to connect a voltmeter to a circuit when making a measurement.

Students examine the procedure to measure current with an analog ammeter. The use of Function and Range switches is explored along with reading the needle position on the meter scale. A brief quiz completes the activity.

In this highly interactive object, learners associate basic line types and terms with engineering drawing geometry. A quiz completes the activity.

Learners examine the basic types of dimensioning including unidirectional and aligned systems, and linear, aligned, angled, arrowless, chain, datum, chart, tabular, radius, diameter, typical, and reference dimensions.

In this interactive and animated object, learners examine orthographic projection and the Glass Box Theory. Front, side, and top view development is demonstrated with pictorial views of each object to help develop 2D to 3D visualization skills.

The learner will practice reading a Vernier caliper.

Are you as smart as a fourth grader? Test your basic Common Core Math vocabulary and find out!

You'll practice converting between units of measure for weight in the English Measurement System.