Photon Energy Calculator:
Enter the values of Planck’s constant, h(J*s), speed of light, c(m/s) and wavelength, λ(nm) to determine the value of Photon energy, E(J).
Photon Energy Formula:
Photon energy refers to the energy carried by a single photon, the quantum particle of light and electromagnetic radiation. The energy of a photon is directly proportional to its frequency and inversely proportional to its wavelength. This relationship connects the wave and particle properties of light.
Photons do not have mass; their energy is purely due to their motion, characterized by the Planck-Einstein relation. The constants involved in photon energy calculations are Planck’s constant (h), which defines the scale of quantum effects, and the speed of light (c) in a vacuum.
Photon energy plays a fundamental role in various physical processes, such as photosynthesis, photoelectric effects, and communication technologies. It is typically measured in electron volts (eV) or joules (J), where 1 eV equals 1.602 * 10−19 J.
The energy of a photon decreases with increasing wavelength, as longer wavelengths correspond to lower frequencies. This relationship highlights the dual wave-particle nature of light and its quantized behaviour in energy interactions.
Photon energy, E(J) in Joules is calculated as the product of Planck’s constant, h(J*s) in Joules second and the speed of light, c(m/s) in metres per second divided by the wavelength, λ(nm) in nanometres.
Photon energy, E(J) = h(J*s) * c(m/s) / λ(nm)
E(J) = photon energy in Joules, J.
h(J*s) = Plancks’s Constant in Joules second, J.s.
c(m/s) = speed of light in metres per second, m/s.
λ(nm) = wavelength in nanometres, nm.
Photon Energy Calculation:
1.A photon has a wavelength of500nm. Calculate its energy in joules.
Given: h(J*s) = 6.626 * 10−34J.s, c(m/s) = 3 * 108, λ(nm) = 500nm.
Photon energy, E(J) = h(J*s) * c(m/s) / λ(nm)
E(J) = 6.626 * 10−34 * 3 * 108 / 500
E(J) = (1.9878 * 10−25) / 5 * 10−7
E(J) = 3.9756 * 10−19J.
2.A photon has energy 4.0eV. Calculate its wavelength in nanometres.
Given: h(J*s) = 6.626 * 10−34J.s, c(m/s) = 3 * 108, E(J) = 4 * 10−19J.
Photon energy, E(J) = h(J*s) * c(m/s) / λ(nm)
λ(nm) = h(J*s) * c(m/s) / E(J)
λ(nm) = 6.626 * 10−34 * 3 * 108 / 4 * 10−19
λ(nm) = 1.9878 * 10−25/ 6.408 * 10−19
λ(nm) = 310nm.