Answer: As a red photon has a twice of the wavelegth to the violet photon then the red photon has half energy of the violet photon.
Explanation: In order to explain the above statement we have to consider the Plack postulate where the energy of photons depend directely of the frequency . As the wavelength and frequency are related by :
c= λ*υ c is the speed of light, λ is the wavelength and υ the frequency of the photon
so the energy of photons are inversely proportional to the wavelength.
As a consequence twice wavelengtht means half energy for the photon.