What is the photon energy of that light?

Question

The meter was once defined as 1 650 763.73 wavelengths of the orange light emitted by a source containing krypton-86 atoms. What is the photon energy of that light?

Answer 1

Energy of a photon E = h ϒ

 

Where h= Plank's Constant  and ϒ is frequency

 

But Frequency = Velocity / Wave length

 

So E = hc/Wave length

 

      (6.63 x 10 ^-34 x 3 x10⁸) / Length of one wave

Given wave length = 1/ 1650763.73

 

E = 6.63 x 10^-34 x 3x 10⁸x 1650763.73 Joules

 

= 32833690.5897x 10 ^-26 = 3.28 x 10 ^-19 J approx