Copper is a material that easily accepts electrons while zinc is a material that easily gives up electrons. This promotes a flow of electrons. When two different types of metal strips are placed into an acidic solution, a chemical reaction may take place between the solution and the metals. A chemical reaction in which electrons are accepted by one material and given up by another material is called an oxidation-reduction reaction, and results in the flow of electrons. The process of chemical reactions using or producing electricity is electrochemistry.