Lemon battery that lights an LED

How to make it

1. 

   1

   Squish the lemons

   Roll each lemon firmly on the table to get the juice moving inside.

2. 

   2

   Push in the metals

   Push a nail into one end of each lemon and a copper piece into the other. Keep them about 1 in apart and not touching.

3. 

   3

   Link the lemons

   Clip the nail of lemon 1 to the copper of lemon 2. Keep going: nail to copper, all the way to lemon 4.

4. 

   4

   Find the ends

   You'll have 1 copper and 1 nail left with no wire. Clip a wire to each.

5. 

   5

   Light it

   Clip the copper wire to the LED's long leg and the nail wire to the short leg. Turn off the room light and look closely.

6. 

   6

   Troubleshoot

   No glow? Flip the LED around, check every clip, or add a 5th lemon.

7. 

   7

   Talk about why

   Zinc and copper trade electrons through the lemon juice. That moving charge is electricity. One lemon makes less than 1 volt, so you chain them to add up enough.