Question

What is the energy (in joules) of an ultraviolet photon with wavelength 110 nm?

Answer 1

For light or ultraviolet, the formula for energy can be calculated using Planck’s equation. That is:

E =  h c / ʎ

where,

h is the Planck’s constant = 6.626 * 10^-34 m^2 kg / s

c is the speed of light = 3 * 10^8 m/s

ʎ is the wavelength of light = 110 nm = 110 x 10^-9 m

 

So calculating for energy E:

E = (6.626 * 10^-34 m^2 kg / s) * (3 * 10^8 m/s) / (110 x 10^-9 m)

E = 1.807 x 10^-18 J