Sulfur vapor is analyzed by photoelectron spectroscopy (PES). Measurements determine that photoelectrons associated with the 1st ionization energy of sulfur move with de Broglie wavelength λ=3.591 A˚. What is the maximum wavelength (in meters) of radiation capable of ionizing sulfur and producing this effect?

Answer 1

How is this calculated? someone to give the little formula

Answer 2

p=h/lambda(meters) ,
E= p^2/2m + 1.659*10^-18,
LambdaMax=hc/E