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Photon Energy Equation:
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The photon energy equation E = hc/λ relates the energy of a photon to its wavelength, where h is Planck's constant, c is the speed of light, and λ is the wavelength. This fundamental equation in quantum mechanics describes the energy carried by electromagnetic radiation.
The calculator uses the photon energy equation:
Where:
Explanation: The equation shows that photon energy is inversely proportional to its wavelength - shorter wavelengths correspond to higher energy photons.
Details: Calculating photon energy is essential in fields like spectroscopy, quantum mechanics, photochemistry, and optical engineering. It helps determine the behavior of light-matter interactions and is fundamental to understanding phenomena like the photoelectric effect.
Tips: Enter the wavelength in meters. For common light wavelengths, remember that visible light ranges from approximately 380-750 nanometers (3.8×10⁻⁷ to 7.5×10⁻⁷ m).
Q1: What are typical energy values for visible light?
A: Visible light photons have energies ranging from approximately 1.65 eV (red) to 3.26 eV (violet), or 2.64×10⁻¹⁹ to 5.22×10⁻¹⁹ Joules.
Q2: How does this relate to photon frequency?
A: The equation can also be written as E = hν, where ν is frequency, since c = λν. The two forms are equivalent.
Q3: Why is the energy value so small?
A: Individual photons carry extremely small amounts of energy, which is why we typically measure light energy in terms of large numbers of photons.
Q4: Can I calculate energy in electronvolts instead of Joules?
A: Yes, you can convert the result by dividing by 1.602×10⁻¹⁹ (since 1 eV = 1.602×10⁻¹⁹ J).
Q5: What if I have wavelength in nanometers instead of meters?
A: Convert nanometers to meters by multiplying by 10⁻⁹ before entering the value (e.g., 500 nm = 5×10⁻⁷ m).