In this interactive object, learners use the ideal gas law to solve a practice problem.

In this animated object, learners examine neutral fats, phospholipids, and cholesterol. The molecular formula and general function for each are shown.

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.

Practice how to make research decisions using the 3 Rs.

In this animated activity, learners compare the van der Waals equation with the Ideal Gas Law.

In this animated and interactive object, learners examine the red blood cell's life cycle and function. A brief exercise completes the activity.

Learners assign oxidation numbers to atoms in neutral compounds and in polyatomic ions. Six examples are worked through in detail, and three problems are provided.

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 video learners view the valves and chambers of the heart.