Determine the energy of a photon of green light, which has a wavelength of 550 nm in a vacuum.

λ = 550 nm = 5.5 × 10 ^ -7 m;

The photon energy is calculated by the Planck equation:

E = h * ν, where

h – Planck’s constant, 6.626 × 10 ^ ³⁴ J · s

ν is the radiation frequency.

The radiation frequency is related to the wavelength λ by the ratio:

ν = s / λ,

where c is the speed of light, 3 × 108 m / s.

E = h * s / λ = (6.626 × 10 ^ ⁻³⁴) × (3 × 10 ^ 8) / (5.5 × 10 ^ -7) = 3.61 × 10 ^ -19 J.

Answer: E = 3.61 × 10 ^ -19 J.