Charge of an electron in Coulombs?

AI Thread Summary
The charge of an electron is correctly stated as -1.602176565(35) x 10^-19 C. When calculating current using the formula I = Q / t, the negative sign of the electron's charge does not affect the current's direction, which is defined as the flow of positive charge. Consequently, if electrons move in one direction, the conventional current flows in the opposite direction. The discussion clarifies that while the charge of an electron is negative, the total charge can still be expressed positively when considering the absence of electrons in a neutral object. Overall, the focus is on understanding how current is defined and calculated despite the negative charge of electrons.
mosad655
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Is it correct that the charge of an electron in Coulombs is

- 1,602 176 565(35) • 10-19 C ?

By inserting this in the formula for current I = Q / t, that would make the current a negative number. I don't reckon having read about negative currents though. So what's the explanation for how the negative sign dissappears and currents end up always being positive?
 
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mosad655 said:
So what's the explanation for how the negative sign dissappears and currents end up always being positive?
Current is usually defined as flowing in the direction of positive charge carriers. (Historically, it wasn't anticipated that the charge carriers in a wire, for instance, were actually negatively charged.) So if electrons move to the right, the current is defined as moving to the left.
 
but is it correct that the charge of an electron in Coulombs is - 1,602 176 565(35) • 10^-19 ?
 
mosad655 said:
but is it correct that the charge of an electron in Coulombs is - 1,602 176 565(35) • 10^-19 ?
Sure.
 
so let's say.. 18 C would be then be 18 / (- 1,602 176 565(35) • 10^(-19)) electrons? That's a negative number, how is it possible to have a negative number of electons?
 
mosad655 said:
so let's say.. 18 C would be then be 18 / (- 1,602 176 565(35) • 10^(-19)) electrons? That's a negative number, how is it possible to have a negative number of electons?
What's 18 C? Obviously not the charge on a bunch of electrons. Realize that if something ordinarily neutral is missing a number of electrons, that it will have a positive charge.

What problem are you trying to solve?
 
In the textbook that I have, it comes with this example:

A 5 amp current flows for an hour. The total charge that passes by in such case, is Q = I • t = 5 A • 3600 s = 18000 C or 18000 Coulombs. Now how many electrons is that?
 
mosad655 said:
In the textbook that I have, it comes with this example:

A 5 amp current flows for an hour. The total charge that passes by in such case, is Q = I • t = 5 A • 3600 s = 18000 C or 18000 Coulombs. Now how many electrons is that?
Just divide by the magnitude of the electron charge. Don't get hung up with signs.
 
So coulomb is not the unit for charge, but the unit for the magnitude of charge?
 
  • #10
mosad655 said:
So coulomb is not the unit for charge, but the unit for the magnitude of charge?
You can think of it that way. That's why the charge on the electron is a negative number of Coulombs.
 

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