Table of Contents
What is the equation that relates the energy of a photon to its frequency?
E = h ν
The energy associated with a single photon is given by E = h ν , where E is the energy (SI units of J), h is Planck’s constant (h = 6.626 x 10–34 J s), and ν is the frequency of the radiation (SI units of s–1 or Hertz, Hz) (see figure below).
How do you calculate the energy of a photon of electromagnetic radiation?
h is Planck’s Constant, f is the frequency, c is the speed of light, and λ is the wavelength of the radiation.
- EXAMPLE 1. Calculate the energy of a photon of radiation whose frequency is 5.00×1014Hz .
- Solution 1. E=hf=6.626×10−34J⋅s ×5.00×1014s−1 =3.31×10−19J.
- EXAMPLE 2.
- Solution 2.
What is the energy in joules and electron volts of a photon of 420 nm violet light?
KEe=hν–Φ=2.96eV–2.71eV=0.246eV. The energy of this 420-nm photon of violet light is a tiny fraction of a joule, and so it is no wonder that a single photon would be difficult for us to sense directly—humans are more attuned to energies on the order of joules.
Which type of electromagnetic radiation is highest in energy?
Gamma rays
Gamma rays have the highest energies and shortest wavelengths on the electromagnetic spectrum.
How do you calculate eV frequency?
So 1 eV = (1.6 x 10^-19 coulombs)x(1 volt) = 1.6 x 10^-19 Joules. Now let’s calculate the frequency of the 1 eV photon. E = hf, so f = E/h. Hence, f = 1 eV/6.63 x 10-34 Joule-sec x (1.6 x 10-19 Joule / 1 eV) = 2.41 x 1014 sec-1 or 2.41 x 1014 Hz ( Hz means 1/sec).
What is the energy of therapeutic electrons expressed in MeV?
Whereas, the energy of therapeutic electrons is expressed in terms of MeV. In first case, this voltage is the maximum electric potential used by a linac to produce the photon beam. The beam has a spectrum of energies: the maximum energy is approximately equal to the beam’s maximum electric potential times the charge of the electron.
What is the difference between eV and MeV?
A MeV is the Mega electron-volt, e.g. million times more than eV. One eV is defined as the energy, that an electron (or an other single-charged (q=1.6*10^-19 Coulombs) particle) gains when it undergoes a potential difference of 1 Volt. In the International units (SI units) 1eV corresponds to 1.6*10^-19 Joules.
What does the unit MV mean in radiology?
The unit MV (and for that matter kV) is supposedly strictly applied to x-ray generation although I understand you can see it being used in describing a radionuclides when their energy exceeds 1MeV. (Khan 1994) The MV designates a heterogeneous photon beam spectrum produced by an electron beam (of the same number MeV) striking a target.
What is the difference between MeV and bremsstrahlung?
On the other hand, photons emitted from a breamsstrahlung device such as an X-ray tube or a linear accelerator has an energy spectrum with energies from 0 up to the energy of the electrons creating the bremsstrahlung. Photons emitted from a radioactive decay would properly be labeled MeV because they are mono-energetic.