Aim - To compare the effect
of white light and u.v. radiation on a charged electroscope.
Instructions
The electroscope can be charged positively or negatively using acetate or
polythene rods.
Without the zinc plate in place, charge the electroscope with a positve charge.
Shine white light, then ultra violet light on the top plate of the electroscope and
observe the effect, if any.
Repeat this for a negative charge on the electroscope.
Add the zinc plate (which has been rubbed to remove any oxide layer). Observe the
effect, if any, when white light and then ultra violet light is shone on the plate.