Learners convert units used to designate pressure. Units for pressure are atm, mm Hg, torr, and pascal.

The definition of an isotope is illustrated using the three isotopes of carbon. The three isotopes of hydrogen are discussed as exceptions.

In this interactive object, learners determine the limiting reagent and the excess reagent in chemical reactions. Learners test their knowledge by solving three problems.

Learners read definitions of atomic symbols, atomic numbers, and mass numbers and then answer questions about the number of neutrons, protons, and electrons in select elements.

In this animated lesson, learners read about the disulfide bond, the second strongest chemical bond in the hair. This bond can only be altered by chemicals.

In this animated object, learners examine the properties of the peptide bond and how the bond relates to the structure of hair.

In this learning activity you'll review the six different ways in which electricity is produced: chemical, friction, heat, light, magnetism, and pressure.

In this animated object, learners examine how the heating or cooling steps in a manufacturing process work to control a chemical reaction.

In this animated object, learners examine the kinds of physical and chemical changes that occur in substances. They practice identifying examples of each.

Element Symbols 1-20

Test your recognition of science lab equipment

Choose the correct word or definition of the terms.