What is the energy of light in kJ with a wavelength of 662 nm?

Question

Plz solve it specially chemicals experts 

Answer 1

E = hν where:

• E = the photon's energy
• h = Planck's Constant = 6.62*10^-34 Joule seconds
• v = the photon's frequency

 

The frequency (v) is related to wavelength by the relation λν = c where:

• λ = the photon's wavelength = 662 nm = 6.62*10^-7 m
• ν = the photon's frequency
• c = the speed of light in a vacuum = 3*10⁸ m/s

 

We can solve for frequency: v = c/λ, so:

 

      E = hν = hc/λ

      E = (6.62*10^-34)(3*10⁸)/(6.62*10^-7) = 3*10^-19 joules = 3*10^-22 kilojoules (kJ)