what happens when you touch a Van de Graaff generator?

Answer 1

When you approach a giant Van de Graff generator, because of the presence of a huge surplus of negative charges on the ball, a surplus of positive charges build up on your person, and this causes your hair to stand up. Then, like little ants creating a pathway, ions leak through the air from the ball to you, and vice versa, until sufficient ionic flow occurs to create a temporary and ragged corridor of plasma, which has extremely low electrical resistance as compared to that of free air. Suddenly, the dam has been broken, and there's a sudden rush of surplus electrons from the ball to your person, frequently followed by another rush of surplus ions back to the ball. What has happened is a bolt of lightning, and curing this creation of the plasma and rush of charged particles, ultraviolet light and x-rays are produced, giving it the brilliant blue burst of light. Molecules on your person are stripped of their ions and temperatures rise due to electrical resistance, causing burns. Sheet overflows of electrons pass over your body, but sufficient electrostatic potential build up inside in it, disrupting not only cardioelectric currents, but sometimes causing even internal cavitation. After the neutralization of the electrical charges, the plasma corridor implodes, causing a sonic shock wave, which reaches your ears, and you hear it, as your heart convulses. So, pay attention to the size of the Van de Graff generator you're touching.

Answer 2

The electrons being built up in the generator jump onto you since you're grounded so you get a little zap. If you put your hands on it, your hair will stand up on end.