help.. positively charged (1 Viewer)

[buttercup]

why isnt there a reaction on a positively charged electroscope when UV light shines on it?

 

[buttercup]

oh, and one more thing, in the same scenario, what would happen if the UV was replaced with IF light?

 

[BlackJack]

photoelectric effect... electrons are more tightly attracted to the positively charged nucleus. The UV rays does not have enough energy to give the e- enough 'velocity' to escape orbit, since the attraction by the nucleus is stronger than a neutral or negatively charged metal.

These electrons are closer to the nucleus because there's less of them (which is why the metals is opsitively charged).

IF light has even less energy.

 

[1234567]

hm...
what?
i didn' tunderstand the reply

IF no reaction in this case. too weak.

 

[BlackJack]

Simple put, there is a set amount of energy required to knock the electron out of orbit. With positively charged metals, this energy is higher because of attraction.

 

[1234567]

why is that u ned more energy to get positive charges off?

 

[BlackJack]

You can't get positive charges off. Only the electron does the moving.
The positive charge comes from the extra protons. When a metal is positively charge, it means there's les electrons than there normally is.

 

[1234567]

o .................