A photon has energy of 4.20 eV. To what wavelength does this energy correspond?
A) 321 nm
B) 103 nm
C) 296 nm
D) 412 nm
E) 420 nm

Question

Quizplus · Accepted Answer

The energy of a photon is given by the equation E=hc/λ, where h is Planck's constant (6.626 x 10^-34 J*s), c is the speed of light (2.998 x 10^8 m/s), and λ is the wavelength of the photon. 
Rearranging this equation to solve for λ, we get λ=hc/E. 
Plugging in the values given in the question, we get: 
λ=(6.626 x 10^-34 J*s x 2.998 x 10^8 m/s)/(4.20 eV x 1.602 x 10^-19 J/eV) 
λ=296.1 nm, which is closest to choice C.

A Photon Has Energy of 4