v=E/h v is the frequency h is the planks constant which is 6.626 x10^-34 v is therefore [2.668 x 10^-19] /6.626 x10^-34=4.027 x10^14 c(speed of light)=wavelength x frequency c is always =3.0 x10^8 therefore wavelength = ( 3.08 x10^8)/4.027 x 10^14=7.649 x10^-7 convert to nm =(7.649 x10^-7) x(1.0 x 10 ^9 nm)=764nm
