In this interactive object, students examine a type of chemical bond known as the "hydrogen bond."

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 meaning of oxidation, reduction, and half-reaction, and watch a film showing the deposition of copper metal from the reduction of copper (II) ion by aluminum. A brief quiz completes the activity.

Learners observe that the volume of one mole of any gas is 22.4 L at standard temperature and pressure. An illustration shows that only the mass of the molar volume differs with the identity of the gas.