Sharon Gross, age 13, of Missoula, Mont., for her question:

WHAT IS ELECTROCHEMISTRY?

Electrochemistry deals with the chemical effects of elsctricty sad electrical phenomena resulting from chemical changes. These are most easily studied in solutions of electrolytes, which are substances that conduct electricity when dissolved or melted.

Electrochemistry involves the study of ions in gases, solutions, molten substances and some crystals. Ions are atoms or groups of atoms that carry electrical charges. The ions make it possible for electric current to pass through these substances.

An important subject of electrochemistry is the conversion of chemical energy to electricity. This occurs in dry cells used in flashlights and in automobile batteries.

Electrochemisty also studies corrosion, which is the gradual destruction of metallic surfaces by the action of gases in the atmosphere. By studying corrosion processes, scientists can find effective ways to protect metals.