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.

In this interactive object, learners demonstrate the proper tightening sequence for mechanically joining two mating surfaces.

This screencast, we see how the shape of a stain defines the angle of impact. In general terms the more circular the stain, the more perpendicular will be the angle at which it struck the surface. The more elliptical the shape of the stain, the more acute the angle will be. With practice and experience, the analyst can recognize the general angle of impact based solely on the shape of the stain.

In this screencast, you'll review definitions of To, Too, and Two and review practice sentences.

In this learning activity you'll identify identify two-dimensional geometric shapes in a matching exercise.

In this learning activity you'll factor problems using the difference of two perfect squares.

The student reviews definitions of to/too/two and completes a practice exercise.

Learners examine how five or six groups of electrons around a central atom cause the shape of the molecule to be trigonal bipyramidal, seesaw, T-shaped, linear, octahedral, square pyramidal, or square planar. Seven examples and three interactive questions are provided in this animated activity.

In this animated object, learners examine the signals produced by sourcing and sinking two-wire sensors. A brief quiz completes the activity.

Learners complete two exercises. In the first quiz, they divide viruses into two categories: RNA and DNA. They later match each virus with the disease it causes.

In this animated activity, learners observe how a two-roll metering system operates.

This document is a visual and text description of lathe cutting tool shapes.

In this interactive object, learners examine sectional views used in engineering drawings. The sections shown are full, half, offset, aligned, revolved, and broken-out. Learners match drawings of sectional views with the names of the views.

The learner will understand the two methods used to create a phase shift in current between two windings.

In this learning activity you'll solve systems of two linear equations in two unknowns by determinants.

Learners examine how the two-roll metering system works.

In this learning object you'll explore how agents of socialization shape a person's life and you'll map the significant events, places, and people that have shaped your life.

In this interactive object, learners examine the neuron pathway into and out of the spinal cord. They complete the activity by testing their knowledge of vocabulary and the location of spinal cord structures.

In this animated object, learners examine how to find the center of gravity of a steel rod and of a two-dimensional shape.

Learners read about the purposes of balance sheets and income statements and then place accounts into these two financial statement categories in a drag-and-drop exercise.