# Why is the conversion from eV to Kelvin so high?

• Questions554
In summary, temperature is defined for many particle systems and the energy equivalent is the average energy of those particles. When 7eV corresponds to a temperature of 81121 K, it means that the average energy of particles in a system with that temperature is 7eV. This can vary depending on the system's degrees of freedom, such as translational, rotational, and vibrational. The Boltzmann distribution can determine the fraction of particles with a particular energy. The difference between kinetic and electric energy can also affect the overall energy of the system.
Questions554
I mean eV are something like 1.6x 10^-19 joules but somehow 7eV corresponds to 81121 K?? At that temperature you should have a lot more energy than 7eV! No?

Temperature is soemthing which can be defined for only many particle systems, you need to have at least a few hundread particles, if not more!
Then, the energy equivalent to a particular temperature is interpreted as the average energy of those particles. So when you say 7eV corresponds to 81121 K, it means that in a many particle system with such a temperature, the average energy of particles is 7eV. Some particles have much more energy and some much less.

Questions554
Shyan said:
Temperature is soemthing which can be defined for only many particle systems, you need to have at least a few hundread particles, if not more!
Then, the energy equivalent to a particular temperature is interpreted as the average energy of those particles. So when you say 7eV corresponds to 81121 K, it means that in a many particle system with such a temperature, the average energy of particles is 7eV. Some particles have much more energy and some much less.

Ah cool, does this have to do with the mean of a Boltzmann distribution? This would mean 7eV being a vibrational energy?

Questions554 said:
Ah cool, does this have to do with the mean of a Boltzmann distribution? This would mean 7eV being a vibrational energy?
Yeah, Boltzmann distribution tells you what fraction of the particles have a particular energy.
But all the energy doesn't have to be vibrational. It depends on the system. You may have a monatomic gas which can only have translational degrees of freedom. Or you may have something like a water molecule which can rotate around several axis and also has some vibrational degrees of freedom too. Of course the translational degrees of freedom are still present.

Questions554
Shyan said:
Yeah, Boltzmann distribution tells you what fraction of the particles have a particular energy.
But all the energy doesn't have to be vibrational. It depends on the system. You may have a monatomic gas which can only have translational degrees of freedom. Or you may have something like a water molecule which can rotate around several axis and also has some vibrational degrees of freedom too. Of course the translational degrees of freedom are still present.

Ah gotya, but it's still kinetic as opposed to electric which is probably making all the difference. Very cool, thanks man.

## 1. Why is the conversion from eV to Kelvin so high?

The conversion from eV (electron volts) to Kelvin is high because eV is a unit of energy, while Kelvin is a unit of temperature. Temperature is a measure of the average kinetic energy of particles in a substance, while energy is the ability to do work. Therefore, the conversion between these two units involves converting between two different physical quantities, which results in a high conversion factor.

## 2. How is the conversion factor between eV and Kelvin calculated?

The conversion factor between eV and Kelvin is calculated by using the Boltzmann constant, which relates temperature to energy. The conversion factor is equal to the value of the Boltzmann constant in eV divided by the value of the Boltzmann constant in Kelvin. This results in a conversion factor of approximately 8.617 x 10^-5 eV/K.

## 3. Can eV and Kelvin be used interchangeably?

No, eV and Kelvin cannot be used interchangeably because they are units of different physical quantities. eV is a unit of energy, while Kelvin is a unit of temperature. They can be converted into each other, but they cannot be used interchangeably to represent the same value.

## 4. Why is the conversion from eV to Kelvin commonly used in scientific calculations?

The conversion from eV to Kelvin is commonly used in scientific calculations because it allows for a more accurate and precise representation of energy and temperature. Using eV allows for the expression of smaller energy values, which is useful in calculations involving subatomic particles. On the other hand, using Kelvin allows for the expression of larger temperature values, which is useful in calculations involving macroscopic systems.

## 5. Is there a simpler way to convert between eV and Kelvin?

Yes, there are simpler ways to convert between eV and Kelvin. One way is to use an online conversion tool or a conversion chart. Another way is to use the relationship E = kT, where E is energy in eV, k is the Boltzmann constant in eV/K, and T is temperature in Kelvin. This allows for a quick conversion between the two units without the need for complex calculations.

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