# Photon energy and calculating frequency

• MathiasArendru
In summary, the conversation revolved around calculating the energy and frequency of a photon in a light beam. The first step was to convert the energy from electron volts to joules, which was done by multiplying by 1.60*10^-19. The frequency was then calculated using the equation E = hv, with the value for Planck's constant being 6.63*10^-34. The resulting frequency was 5.12*10^14 seconds, which seemed high. However, it was mentioned that converting to wavelength and comparing it to the visible spectrum would provide a better understanding. It was also noted that converting to joules was a task included in the assignment.

#### MathiasArendru

Hello guys, I am having a bit of trouble with some homework

So I am told that a photon in a light beam has an energy og 2,12 eV. First i have to calculate the energy of it in joules, and since 1 eV is 1,60*10^-19 Joules 2,12 eV in joules is just 2,12*1,60*10^-19 = 3.392*10−19 J i got that.
Then i have to calculate the frequency of the light beam. I use the equation E = hv and just isolate v to get v = e/h. When i then plug in the numbers i get v = 3.392*10−19/6.63*10^-34(plancks constant) = 5.12*10^14 seconds. But isn't that a huuuge frequency? Anything I've done worng?

You shouldn't need to convert to joules. You should have a value for Planck's constant that is eV•s.

Also, if you're unsure what a reasonable frequency is, convert it to wavelength, and then see where that wavelength falls on the spectrum and compare that to the question. In this case if you convert to wavelength you'll find that this pretty much in the middle of the visible spectrum.

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Actually you're right haha, when i first heard it, it just seemed like too much and i didnt think about it any further but obviously it is. and converting to joules was a task included in the assignment.
Thanks

## 1. What is photon energy?

Photon energy is the energy carried by a single photon, which is a particle of light. It is directly proportional to the frequency of the light wave, meaning that higher frequency light has more energy than lower frequency light.

## 2. How is photon energy calculated?

The formula for calculating photon energy is E = hν, where E is the energy in joules, h is Planck's constant (6.626 x 10^-34 joule seconds), and ν is the frequency of the light wave in hertz (cycles per second).

## 3. What is the relationship between photon energy and frequency?

The relationship between photon energy and frequency is direct and proportional. This means that as the frequency of a light wave increases, the energy of each photon also increases. Conversely, as the frequency decreases, so does the energy of each photon.

## 4. How does photon energy relate to the electromagnetic spectrum?

The electromagnetic spectrum is a range of all possible frequencies of electromagnetic radiation, including visible light. As we move from lower frequency to higher frequency waves on the spectrum, the energy of each photon also increases. This is why higher frequency waves, such as gamma rays and X-rays, are more energetic and potentially harmful than lower frequency waves like radio waves.

## 5. Can photon energy be converted into other forms of energy?

Yes, photon energy can be converted into other forms of energy through processes such as absorption, emission, and scattering. When a photon is absorbed by an atom or molecule, it can transfer its energy to the particle, causing it to become excited. This can then be released as heat or light in the form of emission. Scattering occurs when photons interact with particles and change direction, transferring some of their energy in the process.