Can someone explain the difference between Volts and Electron Volts?

In summary: Therefore, 1 eV is only worth 1.602 x 10^-19 Joules instead of 6.25 x 10^-18 Joules. In summary, the difference in the number of electrons between a coulomb and an electronvolt is due to the reciprocal of 6.25 x 10^18 in standard form, giving an extra negative power and resulting in a different value for the charge.
  • #1
synoptic
4
0
OK,

Bear with me, I'm a mature student returning to the sciences after a 16 year break...

I'm currently reading up on electricity and cannot, for the life of me, get my head around what 'appears' to be an inconsistency. Obviously my brain isn't 'seeing' the answer properly just yet so I could do with some help.

Basically, if one coulomb has 6.25 x 10 -18 electrons and 1 volt is the potential energy required to carry out 1 Joule of work how is it that 1 eV is only worth 1.602 x 10. -19 Joules? Why not 6.25 X 10 -18 Joules?

I've read around many sites but can't get my brain to shift into the right perspective with this...

Cheers.
 
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  • #2
A electronvolt is the kinetic energy a electron gets when its passed through a 1 volt electrostatic potential difference.

I don't quite follow why you think that amount of energy in relation to a joule should be the same as a electrons charge in relation to a coulomb??
 
Last edited:
  • #3
By the way your exponent is off. 6.25 x 1018 electrons make up one coulomb of charge.
 
  • #4
Ok, this is where I am going wrong obviously. The problem is I need to be un-confused...
 
  • #5
dav2008 said:
By the way your exponent is off. 6.25 x 1018 electrons make up one coulomb of charge.

Quite right, apologies for the typo.
 
  • #6
A volt is one joule/coulomb. The charge of an electron is - 1.6 x 10^-19 coulombs. The energy acquired by one electron being accelerated through a potential difference of one volt is therefore (1 volt) x (1.6 x 10^-19 coulombs) = 1.6 x 10^-19 joules. Thus one electron volt, one eV, is 1.6 x 10^-19 joules.

Hope this helps.
 
  • #7
synoptic said:
dav2008 said:
By the way your exponent is off. 6.25 x 1018 electrons make up one coulomb of charge.
Ok, this is where I am going wrong obviously. The problem is I need to be un-confused...

you're on the right track. you were asking the right question in your initial post. so now ask yourself: what is the reciprocal of 6.25 x 1018 electrons/coulomb?
 
  • #8
rbj wins a big fat cigar :smile:

It's nice when the obvious strikes you in the face :rofl:

Cheers.
 
  • #9
I think you are confused with the extra negative power, i.e from 18 to -19.

the reason is 1 divided by 6.25 gives 0.1602, and writing that in standard form gives 1.602 x 10^-1, giving you an extra negative power, so the charge is not 1.602 x 10^-18 but 1.602 x 10. -19 .
 

1. What is the difference between Volts and Electron Volts?

Volts (V) and Electron Volts (eV) are two different units of measurement for energy. Volts are a unit of electrical potential, or the amount of electrical force required to move one ampere of current through one ohm of resistance. Electron Volts, on the other hand, are a unit of energy commonly used in physics and chemistry to describe the energy of subatomic particles such as electrons.

2. How are Volts and Electron Volts related?

Volts and Electron Volts are related in that one Electron Volt is equal to the amount of kinetic energy gained by an electron when it is accelerated by a potential difference of one Volt. This means that one Electron Volt is equal to 1.602 x 10^-19 Joules of energy.

3. Can you give an example of how Volts and Electron Volts are used?

One example of the use of Volts and Electron Volts is in the study of atoms and their subatomic particles. Scientists may use Electron Volts to describe the energy levels of electrons within an atom, while also using Volts to describe the potential difference between two points in an electrical circuit.

4. Which unit of measurement is more commonly used in scientific research?

In scientific research, both Volts and Electron Volts are commonly used depending on the specific field of study. In electrical engineering and technology, Volts are the more commonly used unit, while in fields such as particle physics and nuclear chemistry, Electron Volts are more frequently used.

5. Is there a conversion factor between Volts and Electron Volts?

Yes, there is a conversion factor between Volts and Electron Volts. One Electron Volt is equal to approximately 1.602 x 10^-19 Volts. This means that to convert from Volts to Electron Volts, you would divide the amount of Volts by 1.602 x 10^-19, and to convert from Electron Volts to Volts, you would multiply the amount of Electron Volts by 1.602 x 10^-19.

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