# Simple energy with photons problem help

• BuBbLeS01
In summary, photons are fundamental particles that make up light and other forms of electromagnetic radiation. They have zero mass and travel at the speed of light. Energy and photons are directly related through the equation E = hf, where E is the energy of the photon, h is the Planck constant, and f is the frequency of the photon. This means that photons with higher frequencies have more energy, while those with lower frequencies have less energy. The energy of a photon is calculated using the equation E = hf, where E is the energy in joules, h is the Planck constant, and f is the frequency in hertz. The energy of a photon is also inversely proportional to its wavelength, meaning that shorter wavelengths have more energy and
BuBbLeS01
Simple energy with photons problem...help!

## Homework Statement

What is the energy of 1.7 mol of photons that have a wavelength of 0.28 μm?

## The Attempt at a Solution

E = HC/W = (6.63e^34)*(3e^8)/0.00000028 = 7.10357e^-21
what do I do with the mol part? I know 1 mol = 6.022e^23 so I tried multiplying it by that but its wrong...do I divide. Or is there something else I have to do?

your approach looks ok. you have 1.7 mol of photons so you have 1.7*(6.022*10^23)
photons

To solve this problem, you will need to use the formula E = hc/λ, where E is the energy of a photon, h is Planck's constant, c is the speed of light, and λ is the wavelength of the photon. Since you are given the wavelength and the number of photons (1.7 mol), you can use the formula to calculate the total energy.

First, you will need to convert the wavelength from micrometers to meters, as the formula requires the wavelength to be in meters. This can be done by multiplying the given wavelength (0.28 μm) by 10^-6. This gives a wavelength of 0.00000028 meters.

Next, you will need to use the Avogadro's constant (6.022 x 10^23) to convert the number of photons from moles to individual photons. This can be done by multiplying the given number of moles (1.7 mol) by 6.022 x 10^23. This gives a total of 1.0234 x 10^24 photons.

Now, you can plug in the values into the formula E = hc/λ. This gives an energy of (6.63 x 10^-34 J s)(3 x 10^8 m/s)/(0.00000028 m)(1.0234 x 10^24) = 1.934 x 10^-16 J.

Therefore, the energy of 1.7 mol of photons with a wavelength of 0.28 μm is 1.934 x 10^-16 J. Remember to always pay attention to units and convert them accordingly to get the correct answer.

## 1. What is a photon?

A photon is a fundamental particle that is the basic unit of light and all other forms of electromagnetic radiation. It has zero mass and travels at the speed of light.

## 2. How does energy relate to photons?

Energy and photons are directly related through the equation E = hf, where E is the energy of the photon, h is the Planck constant, and f is the frequency of the photon. This means that the higher the frequency of a photon, the more energy it carries.

## 3. Can photons carry different amounts of energy?

Yes, photons can carry different amounts of energy depending on their frequency. Photons with higher frequencies have more energy, while photons with lower frequencies have less energy.

## 4. How is the energy of a photon calculated?

The energy of a photon is calculated using the equation E = hf, where E is the energy in joules, h is the Planck constant (6.626 x 10^-34 J*s), and f is the frequency in hertz.

## 5. How is the energy of a photon related to its wavelength?

The energy of a photon is inversely proportional to its wavelength. This means that photons with shorter wavelengths (higher frequencies) have more energy, while photons with longer wavelengths (lower frequencies) have less energy.

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