Question

Calculate the change in energy of an atom that emits a photon of wavelength 2.21 meters. (Planck’s constant is 6.626 x 10-34 joule seconds, the speed of light is 2.998 x 108 m/s)

Answer 1

The Energy of an atom that emits a photon of wavelength 2.21 m is 3.028 × 10⁻¹⁹ J.
I attached the working and the answer to the question below. I hope I was able to help.
Please note that C = speed of light, ν = frequency, λ= wavelength, h = Planck's Constant