Converting eV to Joules vs eV to V

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In summary: For example, if the electron has a KE of 1.602×10-19 J, then it has 1 eV of energy and was accelerated through 1 volt of potential difference. If the electron has a KE of 3.204×10-19 J, then it has 2 eV of energy and was accelerated through 2 volts of potential difference.In summary, an electron volt is a unit of energy equal to the amount of energy gained (or lost) by the charge of a single electron moved across a potential difference of one volt. This is equivalent to 1.602×10-19 joules. Therefore, to convert the kinetic energy of an electron into electron volts, divide the KE in
  • #1
grandpa2390
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Homework Statement


Is this true?

Homework Equations


1 eV = 1.6e-19 J
1 V = 1.6e-19 eV

The Attempt at a Solution



I did a bit of googling and it just seems strange.
eV multiplied by elementary charge = Joules
ev divided by elementary charge = Volts
 
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  • #2
grandpa2390 said:

Homework Statement


Is this true?

Homework Equations


1 eV = 1.6e-19 J
1 V = 1.6e-19 eV

The Attempt at a Solution



I did a bit of googling and it just seems strange.
This is correct: 1 eV = 1.6e-19 J

This is not correct: 1 V = 1.6e-19 eV

http://en.wikipedia.org/wiki/Electronvolt

An electron volt is a certain amount of energy, not voltage. By definition, 1 electron volt is the amount of energy it takes to move 1 electron across a potential difference of 1 volt.
 
  • #3
SteamKing said:
This is correct: 1 eV = 1.6e-19 J

This is not correct: 1 V = 1.6e-19 eV

http://en.wikipedia.org/wiki/Electronvolt

An electron volt is a certain amount of energy, not voltage. By definition, 1 electron volt is the amount of energy it takes to move 1 electron across a potential difference of 1 volt.

By definition, it is the amount of energy gained (or lost) by the charge of a single electron moved across an electric potential difference of one volt. Thus it is 1 volt (1 joule per coulomb, 1 J/C) multiplied by the elementary charge (e, or 1.602176565(35)×10−19 C).
this is from the wikipedia page. what does this mean then if it is not saying one electron-volt is equal 1.6e-19 C * 1 Volt

based on that, 1 ev / 1.6e-19 C = 1 Volt, right? or am I missing something?

edit: or was issue not with the conversion, but with the units in my question?
1 Volt = 1.6e-19 C*eV rather than what I wrote: 1.6e-19 eV

if that be the case, my apologies, I was being hasty with my concern more for the conversion factor than the proper units.
 
  • #4
SteamKing said:
This is correct: 1 eV = 1.6e-19 J

This is not correct: 1 V = 1.6e-19 eV

http://en.wikipedia.org/wiki/Electronvolt

An electron volt is a certain amount of energy, not voltage. By definition, 1 electron volt is the amount of energy it takes to move 1 electron across a potential difference of 1 volt.
The reason I am asking is because I have to calculate the the potential difference an electron would have to be accelerated through to give it a certain wavelength.
so far I have the potential difference = to the kinetic energy divided by 1.6e-19. but that would give a potential difference in electron volts. to convert to volts, shouldn't i divide again by 1.6e-19 Coulombs?

edit: I don't know I am reading something that says an electron gains 1 ev per 1 volt of potential difference. so maybe they are equal for one electron. this is all very confusing.
 
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  • #5
grandpa2390 said:
By definition, it is the amount of energy gained (or lost) by the charge of a single electron moved across an electric potential difference of one volt. Thus it is 1 volt (1 joule per coulomb, 1 J/C) multiplied by the elementary charge (e, or 1.602176565(35)×10−19 C).
this is from the wikipedia page. what does this mean then if it is not saying one electron-volt is equal 1.6e-19 C * 1 Volt

based on that, 1 ev / 1.6e-19 C = 1 Volt, right? or am I missing something?
grandpa2390 said:
The reason I am asking is because I have to calculate the the potential difference an electron would have to be accelerated through to give it a certain wavelength.
so far I have the potential difference = to the kinetic energy divided by 1.6e-19. but that would give a potential difference in electron volts. to convert to volts, shouldn't i divide again by 1.6e-19 Coulombs?

edit: I don't know I am reading something that says an electron gains 1 ev per 1 volt of potential difference. so maybe they are equal for one electron. this is all very confusing.

1 electron volt already assumes a potential difference of 1 volt. Since 1 eV ≈ 1.602×10-19 joules, then divide the kinetic energy in joules by 1.602×10-19 to convert the KE of the electron into electron volts. This number will also be the voltage required to accelerate 1 electron such that it has that wavelength.
 
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What is the difference between converting eV to Joules and eV to V?

The main difference is that eV to Joules is a conversion from a unit of energy to another unit of energy, while eV to V is a conversion from a unit of energy to a unit of voltage. This means that eV to Joules is used to measure the amount of energy in a system, while eV to V is used to measure the potential difference between two points.

Why do we need to convert between eV and Joules or eV and V?

Converting between units is necessary to compare and communicate measurements accurately. In scientific research, different units may be used to measure the same quantity, so having conversions allows for consistency and easier understanding.

How do I convert eV to Joules?

To convert from eV to Joules, you can use the conversion factor 1 eV = 1.602 x 10^-19 Joules. Simply multiply the number of eV by this conversion factor to get the equivalent value in Joules.

How do I convert eV to V?

To convert from eV to V, you can use the conversion factor 1 eV = 1.602 x 10^-19 V. This means that 1 eV is equal to a very small amount of voltage. To convert, simply multiply the number of eV by this conversion factor to get the equivalent value in V.

Can eV and Joules or eV and V be used interchangeably?

While eV, Joules, and V are all units of energy, they cannot be used interchangeably. Each unit has a specific definition and conversion factor, so using them interchangeably would lead to incorrect measurements and calculations.

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