Dry Lab Activity

Unit D - Chapter 11

Investigating Science 9

Inquiry Activity

Electricity Grows on Trees

Skills Reference 2

Skills you Will Use

  • Using appropriate equipment and tools
  • Drawing conclusions


  • Sharp Objects


In this lab you will be using sharp pieces of wire and nails, so take care not to poke yourself.

The production of voltage from an electrochemical cell requires an electrolyte and two different electrodes. The electrolyte is a substance that attacks one or both of the electrodes, resulting in the movement of electrons.

As it turns out, many fruit and vegetables contain natural juices that can serve an electrolyte. For example, a common hobby science kit that can be purchased is a potato clock.

In this activity, you will use apples to create electrochemical cells and use them to try to power a calculator.


How can you make a wet cell out of common household materials?

Materials and Equipment

  • 2 galvanized nails about 10 cm long
  • 2 copper wires about 10 m long
  • 4 30-cm insulated connecting wires with bare ends
  • 2 marble-sized lumps of clay
  • 4 clothes pins
  • 2 apples
  • calculator powered by a single 1.5-V dry cell

Dry Lab

A "dry lab" activity includes collected data and/or a video solution for your convenience. You can simply watch the following video and use the provided data, or if you wish to perform this lab for yourself, follow the procedure steps 1 through 9 described in the video. The same steps are included in written form in the documents available for download on the bottom of this page.

Analyzing and Interpreting

  1. A student performing the procedure steps 1 through 9 found that the calculator would not operate with only one apple battery, but when two apple batteries were connected in a particular way, the calculator worked. If you performed this experiment, comment on whether or not these results agree with yours, and why the calculator works with two apple batteries, but not one.
  2. Draw the parts of the wet cell you constructed and label the electrodes and electrolyte.

Skills Practice

  1. Design an experiment that compares different types of fruits in wet cells and their ability to produce electrical current.

Forming Conclusions

  1. Explain how the experimental wet cell in this investigation is similar to a wet cell you might purchase in a store to provide electrical energy for starting your car.