Most of our favorite things like toys, cars, phones, watches and speakers need batteries to survive! The devices stop working and are termed dead when their batteries exhaust. So, why don't you learn to make a battery at home with a few simple supplies and understand its functionality with this cool science fair project idea?
Use a clipper to take off about 2 1/2 inches of plastic insulation that's found on the copper wire. Now, clip the loose piece off the main roll.
Use all your strength to straighten the steel paper clip. Ask an adult for assistance to help you straighten it. Measure it at 2 1/2 inches and cut off the remaining.
Rub off any rough spots in the wire or the paperclip with sandpaper. Make sure it's smoothened perfectly.
Now, roll the orange in your hand to loosen up the juice inside. You can also roll it on a flat surface to break the cell walls as you will need the juice to form the foundation of this science fair project.
Stick the copper wire about 1 inch into the orange. Moisten your tongue with saliva and lightly touch the wire. Do you notice any distinct taste?
Now, carefully stick the paper clip and zinc strip into the orange about 1/4 inch next to the wire making sure no metal touches another. Again, touch the wire ends with your tongue. What do you notice this time?
There must have been a distinct difference in taste when you touched your tongue to the copper wire and then all the metals and alloys. While just the copper wire was plain, the metals and alloy were metallic to taste.
Why did you feel the metallic taste?
The orange battery was generating electricity which means the electrons from the wire were travelling to your tongue. The electrons moved across the surface of the tongue and hence you got the metallic taste. Electrons are smaller breakdowns of an atom and are electrically charged.
The kind of battery that you made is called a voltaic battery. It is made of two different metals which act as electrodes, passages from where any current is transferred. Since electrolytes(sour acid from the orange and the saliva) transfer electricity when dissolved in water, you felt the tingling taste because your mouth was moist, as was the orange. Batteries stop working when there aren't enough electrolytes to react with metals or not enough metals to react with the electrolytes.
· Connect multiple orange batteries to generate more electrical current. Use a copper wire to connect the two as a bridge.
· Use variables and repeat the science fair project idea with a variety of acidic fruits and vegetables and measure which one generates most current.