How Many Electrons Are Removed to Achieve a Positive Charge on an Electroscope?

[ital_dj]

Homework Statement

If an electroscope has a positive charge of 7.5 x 10$$^{-11}$$C, how many electrons have been removed from the electroscope, if it was originally neutral?

(Answer: 4.7 x 10$$^{8}$$)

Homework Equations

I don't know :shy:

The Attempt at a Solution

Guys I seriously am clueless with this question. I understand basic electricity a little, like circuits, but I don't even know where to start with this. I have all formulas required, but I don't know which one to use, and my exam is tomorrow

There are also some other questions which I'll probably post later, I'm really stuck on this, and your help is appreciated... a lot!

Thanks

 

[Redbelly98]

What is the charge of a single electron?

 

[ital_dj]

-1?? I don't know to be honest with you.

 

[rock.freak667]

-1?? I don't know to be honest with you.

an electron has a charge of $-1.6 \times 10^{-19}$

 

[ital_dj]

Okay, thanks.. but how do I put that into the question??

 

[rock.freak667]

The charge on the scope= Ne
where N=No of electons and e=charge on one electron

 

[ital_dj]

well... what you told me is like a completely new language to me... thanks for the help, but i really don't understand it (i understand what you're saying but i don't know what to do with that)... is there a specific equation i can use?

EDIT: I'm going to bed, my exam's early in the morning... I guess electricity won't be that great on the exam. Thanks everyone for the help.

 

[Redbelly98]

an electron has a charge of $-1.6 \times 10^{-19}$

It might have been beneficial to include units (Coulombs) in that answer, but anyway it's a moot point now.

 

[ital_dj]

Well I did the exam today so I'm done with physics for now... no need for the answer... I think I did pretty decent on the exam... no questions like that, though.

Thanks everyone for the help.

 

[Gear300]

well...at least everything well

 

[rock.freak667]

Well I did the exam today so I'm done with physics for now... no need for the answer... I think I did pretty decent on the exam... no questions like that, though.

Thanks everyone for the help.

Even though it's up to you to want to know the answer, IMO it's best to understand how to get the answer so in case you are presented with a similar question,you'd know how to get through it.