An experiment that will illuminate the mysteries of ions! Create a cell of electrolyte and metals, and watch how the reactive and non-reactive metals form ion

This practical helps students to grasp the ideas around electromotive force found in chemicals.

This experiment should take 45 minutes.



  • Eye protection
  • Beaker, 100 cm3
  • Galvanometer or voltmeter (0–3 V)
  • Wires x2
  • Crocodile clips x2


  • Sodium chloride solution

Access to strips or rods of various metals, including:

  • Zinc
  • Copper
  • Iron
  • Lead
  • Magnesium

Health, safety and technical notes

  • Read our standard health and safety guidance.
  • Always wear eye protection.
  • Always wash hands after handling lead.
  • Zinc is flammable and dangerous to aquatic life, see CLEAPSS Hazcard HC107.
  • Lead is a reproductive toxin, see CLEAPSS Hazcard HC056.
  • Magnesium is flammable, and reactive with water, see CLEAPSS Hazcard HC059a.


CCE19_Electricity from chemicals_image1

  1. Set up the apparatus as shown.
  2. Record the voltage.
  3. Try all the combinations of metals.
  4. Wash hands after handling lead. 
  5. Complete table.
 Metals used Which metal forms thepositive terminal (+ve) Which metal forms thenegative terminal (-ve) Voltage (V)
 zinc and copper      
 copper and lead      
 lead and iron      
 zinc and lead      
 iron and magnesium      
 zinc and iron      
 zinc and magnesium      
 lead and magnesium      
 copper and magnesium      
 copper and iron      


Data logging sensors and software can be used in this experiment to provide a large screen display of the voltage changes. Connect a voltage sensor across the electrodes and get the software to show the reading using a meter or graph.

Metals high in the reactivity series have a tendency to release electrons to form ions.

Metals low in the series do not readily form ions, and their ions easily form metal atoms.

With zinc and copper:

Zn(s) → Zn2+(aq) + 2e– Cu2+(aq) + 2e– → Cu(s)


  1. Place zinc, magnesium, copper, lead, and iron in order of reactivity


  1. Magnesium, zinc, iron, lead, copper