Physics · University
Photon energy from wavelength · formula reference
Use hc = 1239.84 eV·nm for the stated numerical convention.
Formula
Use hc = 1239.84 eV·nm for the stated numerical convention.
E = hc/λ
Worked example
A photon has wavelength 140 nm. Using hc=1239.84 eV·nm, calculate its energy in eV. Round the final result to 4 decimal places if needed. Answer in eV.
Divide the stated hc by wavelength: 1239.84/140.
8.856 eV
Prerequisites and checking
Algebra, calculus and the stated physical model. Keep units and rounding consistent. State the model conditions before applying the formula.
Further reading and review references
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