Electrodes Our ten-electrode kit is the right mix for science fairs! Includes: carbon rod electrode (one); nickel electrode (one); copper, iron, zinc, aluminum electrodes (two each). The electrodes are 4" x 3/4" each except for the 4" carbon rod. They feature a large surface/mass ratio. 4" electrodes with chemical symbols are sold separately in packs of 10 (zinc is a pack of 5). 2" electrodes are available in copper and zinc, sold individually. Qty :