Converting eV to V: Debunking the Myth and Simplifying the Process

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In summary, the conversation discusses the possibility of converting between electric potential and energy using the equation eV = Q[SUB]electron[SUP] * V. However, it is explained that this is not possible as the units on both sides of the equation do not match. Additionally, the concept of using electron volts to describe the energy of neutral particles is also mentioned.
  • #1
robwashere
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I've done some research on this, but some people say that you cannot convert these two things. They say that V is electric potential, and eV is energy.

What I was thinking was since eV = Qelectron * V, can't you just divide eV by charge of electron to get V?

Sorry if this is a dumb question
 
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  • #2
Umm...how to explain this.
OK, so put it this way. I can convert between meter and foot because they're both distance. Thus, the conversion values are equivalent.
But what you're saying is to convert between two things that have, effectively, little in common. in a conversion, the values must be equivalent. This isn't the case with what you have here.
 
  • #3
robwashere said:
I've done some research on this, but some people say that you cannot convert these two things. They say that V is electric potential, and eV is energy.

What I was thinking was since eV = Qelectron * V, can't you just divide eV by charge of electron to get V?


Sort of. If you have an energy expressed in electron volts, and you know the charge, you get a voltage (a potential difference) when you divide the energy by the charge. Charges are not always equal to the elementary electron charge. For example, an alpha particle is like a helium nucleus, so it has a charge of +2e. So to accelerate an alpha particle to an energy of 1 MeV, you have to have a potential of 500,000 volts.
 
  • #4
Neutral particles such as neutrons or gamma rays are often described using electron-volts to define their energy - there is no charge.
 
  • #5
robwashere said:
I've done some research on this, but some people say that you cannot convert these two things. They say that V is electric potential, and eV is energy.

What I was thinking was since eV = Qelectron * V, can't you just divide eV by charge of electron to get V?

Sorry if this is a dumb question


You're trying to setup an algebraic equation with a unit on one side and a physical relationship on the other, which is not possible.

It would be like saying that [itex]meter = vt + {{1}\over{2}}at^2[/itex], which is clearly nonsensical.
 

1. What is eV and how is it different from V?

eV stands for electron volt and is a unit of energy commonly used in atomic and molecular physics. It is the amount of energy gained by an electron when it moves through a potential difference of one volt. V stands for volt and is a unit of electric potential, or the amount of work needed to move a unit of electric charge from one point to another.

2. Why is there confusion around converting eV to V?

There is confusion around converting eV to V because both units are used to measure different quantities (energy and electric potential, respectively) and are not directly interchangeable. Additionally, the conversion factor between eV and V is not a simple, whole number, making it more challenging to understand and remember.

3. How can I convert eV to V?

To convert eV to V, you can use the conversion factor 1 eV = 1.602 x 10^-19 V. This means that to convert from eV to V, you need to divide the value in eV by 1.602 x 10^-19. For example, if you have a value of 100 eV, to convert it to V, you would divide 100 by 1.602 x 10^-19, resulting in a value of 6.24 x 10^-18 V.

4. Can you give an example of converting eV to V?

Sure! Let's say you have a particle with an energy of 5 eV. To convert this to V, you would divide 5 by 1.602 x 10^-19, resulting in a value of 3.125 x 10^-18 V.

5. Is it necessary to convert eV to V in scientific calculations?

It depends on the specific calculation and the units used in the equation. In some cases, it may be necessary to convert eV to V to ensure consistency in units. However, in other cases, using either eV or V may be appropriate. It is important to pay attention to the units used and make any necessary conversions to ensure accurate results.

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