|DCS# 7A10.10||NWU# A-3||Location: various|
|title: Photo-Electric Effect|
aka: Zinc or lead exposed to UV light
A freshly sanded zinc plate is placed on an electroscope and charged both positively and negatively. The plate is illuminated with UV light. The negatively charged plate discharges, unless a glass filter is placed in front of the UV light. The positvely charged plate does not discharge.
Explain why the positive plate does not discharge.