What is photon energy equal to?
The energy E of a photon is equal to hv = hc/λ, where v is the frequency of the electromagnetic radiation and λ is its wavelength. Energies in quantum physics are commonly expressed in electron volts (1 eV = 1.6 × 10−9 J) and wavelengths are typically given in nanometers (1 nm = 10−9 m).
How do you find the energy of a photon in kJ mol?
Thus the energy carried by a single photon of 535 nm light is 3.71 × 10−19 J. The conversion to kJ/mol involves using Avogadro’s number and converting J to kJ: E (kJ/mol) = (3.713 × 10−19 J/photon)(6.022 × 1023 photon/mol)(10−3kJ/J) = 224 kJ/mol.
How do you go from kJ mol to J photon?
The conversion to kJ/mol involves using Avogadro’s number and converting J to kJ: E (kJ/mol) = (3.713 × 10−19 J/photon)(6.022 × 1023 photon/mol)(10−3kJ/J) = 224 kJ/mol.
What does a photon energy unit of a Joule equal?
When dealing with “particles” such as photons or electrons, a commonly used unit of energy is the electron-volt (eV) rather than the joule (J). An electron volt is the energy required to raise an electron through 1 volt, thus a photon with an energy of 1 eV = 1.602 × 10-19 J.
How do I find my kJ photon?
How many kJ are in a mole?
The prefix “kilo” means 1,000, so one kJ = 1,000 J. As the energies associated with a single molecule or atom are quite small, we often find it easier to discuss the energy found in one mole of the substance, hence “per mole”. To get the energy for one molecule, divide kJ/mol by Avogadro’s number, 6.022 x 1023.
How do you convert kJ mol to J photon?
The conversion to kJ/mol involves using Avogadro’s number and converting J to kJ: E (kJ/mol) = (3.713 × 10−19 J/photon)(6.022 × 1023 photon/mol)(10−3kJ/J) = 224 kJ/mol. Exercise: Calculate these same quantities using the value of ν for 535 nm radiation that was obtained in the first example above.
How do you find the energy of one photon?
To find the energy of a photon, multiply Planck’s constant by the speed of light, then divide by the photon’s wavelength. For a mole of photons, multiply the result by Avogadro’s number.
What does kJ mean in physics?
Thus, a kiloJoule (kJ) is 1000 Joules and a megaJoule (MJ) is 1,000,000 Joules. A related unit is the Watt, which is a unit of power (energy per unit time).