Electrical Conductors and Insulators, help

[soulembracer]

Homework Statement

A balloon, initially neutral, is rubbed with fur until it acquires a net charge of -0.60nC. (a) Assuming that only electrons are transferred, were electrons removed from the balloon or added to it? (b) how many electrons were transferred?

Net Charge = Q = -0.60 nC

Homework Equations

Electron Charge = qe = -1.602 x 10^-19 C
*meaning the Charge in 1 Electron = qe

1 nC = 10^-9 C

The Attempt at a Solution

(a) HELP I'm confused in problem a. My book says it is added but it doesn't have any explanation. :( I want to know when electrons are removed or added.

(b) I tried this but I'm not sure if it is correct.
- I converted nC to C for the given net charge:
Q = (-0.60 nC)(10^-9C / 1 nC) = -6 x 10^-10 C or -6 EXP -10 C

-I get the numbers of transferred electrons through this:
No. of Electrons = (Q)(1 electron/qe)

= (-6 EXP -10 C)(1 electron/-1.602 x 10^-19 C)​

*cancel C unit​

=3.75 x 10^9 electron or 3.75 EXP 9 electron​

is this correct? I'm confused because my classmates' answer is different compare to me.

and by the way, this one doesn't have any relation with this problem, what does this mean:
1.0-g
what is -g? It's not a variable. It is just given as it is. It also belong in the topic of Electrical Conductors and Insulators.

Please help.

 

[marlon]

To answer a) Initially the balloon was neutral. That means the net charge was 0 C. Then, after charging it, the balloon acquired a NEGATIVE charge. That means electrons were added. Reason ? Well, electrons have negative charge. It's as simple as that

marlon

 

[marlon]

b) looks ok to me

1.0-g, can you tell me more about where you read this ? What question in your book ? What example ?

marlon

 

[soulembracer]

b) looks ok to me

1.0-g, can you tell me more about where you read this ? What question in your book ? What example ?

marlon

thanks for explaining problem a. I didn't figure it out. :)

regarding 1.0-g:
Suppose a 1.0-g nugget of pure gold has zero net charge. What would be its net charge after it has 1.0% of its electrons removed?

In my understanding, that is in grams, but I wonder why it has negative sign..