Battery (DIY Science Kit)

The Voltaic cell was one of the first batteries to be invented and the principle behind its operation is still used in some modern batteries. A simple 'wet' cell consists of two metal plates, in this case magnesium and copper, separated by a liquid, in this case citric acid solution. Known as the electrolyte, this liquid serves as a channel for balancing the charge between the electrodes when the cell is being discharged. Here, we connect the electrodes (magnesium and copper strips) to an LED, which lights up after the cells are dipped in the electrolyte. This battery of two cells that you have just made, stays lit for hours, even after you remove it from the electrolyte. Once the electrolyte dries up, dip the cells in again, and the LED lights up once more! You may try using different electrolytes like salt water, vinegar, carbonated water or cold drinks, and see if these also light your LED. This model is also a simple and powerful demonstration for the difference in electro-negativity of metals. You may try to build your own cell with iron nails and the copper strip! For a short video, look at https://www.youtube.com/watch?v=2txlzVzWQ5w .