Charge of an electron in Coulombs?

In summary, the charge of an electron in Coulombs is -1,602 176 565(35) • 10^-19. However, current is usually defined as flowing in the direction of positive charge carriers, so it is possible to have a negative number of electrons. When calculating the number of electrons in a given charge, the magnitude of the electron charge is used, which is why the unit for charge is coulombs.
  • #1
mosad655
12
0
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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  • #2
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.
 
  • #3
but is it correct that the charge of an electron in Coulombs is - 1,602 176 565(35) • 10^-19 ?
 
  • #4
mosad655 said:
but is it correct that the charge of an electron in Coulombs is - 1,602 176 565(35) • 10^-19 ?
Sure.
 
  • #5
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?
 
  • #6
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?
 
  • #7
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?
 
  • #8
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.
 
  • #9
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.
 

1. What is the charge of an electron in Coulombs?

The charge of an electron in Coulombs is approximately -1.602 x 10^-19 C.

2. How was the charge of an electron determined?

The charge of an electron was first determined by American physicist Robert A. Millikan in his famous oil drop experiment in 1909.

3. Why is the charge of an electron negative?

The charge of an electron is considered negative because it was initially defined as the opposite of the charge of a proton, which is positive. This convention has been used since the discovery of the electron in the late 19th century.

4. Can the charge of an electron change?

The charge of an electron is considered a fundamental constant of nature and it is currently believed that it cannot change. However, some theories suggest that in certain extreme conditions, such as in the presence of a strong electric field, an electron's charge may be altered.

5. How does the charge of an electron affect its behavior?

The charge of an electron plays a crucial role in determining its behavior in an electric field. Electrons with opposite charges will attract each other, while electrons with the same charge will repel each other. This behavior is the basis for many fundamental principles in physics and is used in various technologies, such as electricity and electronics.

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