Then, attach lead wires to the 2 metal strips to test your battery with a voltage meter! You should also be able to find lead wires at shops that sell electrical components. Connect the zinc electrode to the negative - terminal. Does freshness of the cell make a difference? Batteries consist of two electrodes inserted into an electrolyte solution, and the acidic juice of a lime is a natural electrolyte solution, making it a good source of bio-power. In this application, electricity is produced from a chemical reaction between two dissimilar metal electrodes immersed in an electrolyte solution. This makes citrus fruits perfect for the job. Now, a far more powerful instrument may be made in a snuff box and carried in the pocket. Attach the lead wires to the metal strips.
This difference is what generates electricity. Many pupils will need the help, and money, of an adult to obtain them. Ions flow through the electrolyte and electrons flow through the wire. This result is consistent with the fact that copper atoms from the electrode are not involved in the chemical reaction model for the cell. If you have a Micro Ammeter, you can use it to compare the effectiveness of various fruits in relation to electrical current.
As a group, let them know the same thing that causes the light in a flashlight to come on is what causes the meter to move. If we'd thought of that we would have had spare fruit to make lemonade. Once the single-cell fruit battery demonstration is over, many instructors will ask for ideas on increasing the voltage output. Observation Do you think another kind of fruit would work with this experiment? Consisting of one or more voltaic cells, batteries come in various sizes and forms and are integrated into most electronic and portable devices. The next step is to puncture the citrus fruit with the nails. In this science fair project,construct batteriesfrom various fruits and testthem to see which one will producethe most electric current.
Liquids you can test include orange juice, lemonade, and pickle brine. As a crude comparison: think of the metals at the terminals as buckets of water, interconnected by a hose … by the bottom. Other metals such as lead, iron, magnesium, etc. The reading you see may be different from one lemon to another, and from one trial to the next. Most of the detailed predictions of the model apply to the battery's voltage that is measured directly by a meter; nothing else is connected to the battery. Insert the two electrodes into the fruit, but leave enough sticking out so that you can attach a wire or an alligator clip to it, without the wire coming into contact with the fruit.
Show your audience the voltmeter's original reading of zero volts. The two oxidation-reduction reactions listed above only occur when electrical charge can be transported through the external circuit. The hydrogen molecules formed on the surface of the copper by the reduction reaction ultimately bubble away as hydrogen gas. If it were not for this handy way to store electrical energy, we would not be able to have all of our portable electronic devices, such as phones, tablets and laptop computers. Try using different kinds of fruits and measure the differences between them. Additional information is also discussed in the section.
It's not the fruit that's creating the voltage, but the chemical reaction between the citric acid and the individual nails. I recommend this video from SciShow which explains the science. Add more fruit batteries to the series for better results. There are quite a few things going on that we cannot control, but the important point is that we do get a voltage reading. Zinc and Copper make great battery terminals.
. Connect one of the Micro Ammeter's terminals to the copper nail and attach with a Crocodile clip. It's very quick so you might need to pause a few times to give kids a chance to take it in. The electrons then flow from the zinc strip to the copper strip through an external circuit. The Magazine of Science and School of Arts. If the terminals in our experiment are not connected to the meter, no voltage potential can be read. If you are performing the light bulb project, demonstrate how the battery makes the flashlight bulb come on.
Procedure The estimated experiment time for this activity is about five to ten minutes. While other fruits can be used, the high acidity of citrus fruits makes them the best for these experiments. Your aim is to soften the citrus fruit enough to extract its juices. Wrap the other end of the wire around the copper nail. If so, did the size make the current increase or decrease? Elbrie enjoys learning about technology and sharing her design skills with her two younger children and helping her teenager find the right path for a tech career. Insert the ends of the terminals into the apple a little over an inch deep.
Connect the two electrodes with a material that can transport electricity well called a conductor and the chemical reactions fire up; the battery is generating electricity! Goodisman excludes this reaction as being inconsistent with the experiments, and notes that the correct chemistry, which involves the evolution of hydrogen at the copper electrode but also can use silver instead of copper, has been known for many years. A small copper wire or zinc coated nail may produce a high measurable voltage, but not sufficient current to operate the device. Different combinations of metals as electrodes will influence the amount of electricity generated. Do you think the size of the fruit would effect the voltage? Wiggle the electrode around a little to smash the membranes inside the fruit. The in Copper Cu attract more electrons than the atoms in Zinc Zn.