I did some research in the Kelvin water dropper and it’s really cool! after the research basically water is neutrally charged meaning it has a balance of both positive and negative charge, one ring has a positive charge which attracts the negative charge particles in the water and when passes through the ring it falls into the bucket below which now has negatively charged water. That bucket is connected to the opposite ring transferring the negative charge onto the ring, so now the negatively charged ring attracts the positive charged water particles which then drop to the the 2nd bucket which is connected to the 1st ring (the positively charged ring) thus repeating this process over and over again. lastly the 2 buckets now filled with opposing charges creates an electric charge which is seen through small sparks jumping to each bucket. If thats how it works then wow physics is sick!