Chemistry Wavelength Question HELP! PLEASE!

The extent of crystal field splitting is often determined from visible absorption spectra.

a. Given the wavelength –w- of maximum absorption, find the crystal field splitting energy –delta- in kJ/mol, for each of the following complex ions:
Ion w (nm)
[Ir(NH3)6]3+ 244
[Co(NH3)6]3+ 405
[Rh(NH3)6]3+ 295

b. Use the delta values to state how period number affects crystal field splitting energy.

first, calculate the energy that corresponds to the wavelength in question

C = wavelength x frequency
E = planck's constant x frequency, C = speed of light = 3x10^8m/s
planck's constant = 6.626x10-34J-s
wavelength is in meters.....take nm and either divide by 1x10^9nm/m or add "x10^-9" after the number, example 244nm = 244x10^-9m, shortcut
so
C / wavelength = E / planck's constant
solving for E, we get E = C x planck's constant / wavelength
E = 3x10^8m/s x 6.626x10^-34J-s / 244x10^-9m = 8.147x10^-16J

next, convert J/ion to kJ/mole
8.147x10^-16J/ion x 6.022x10^23 ions/mole / 1000J/kJ = 4.902x10^5kJ

do this for the other 2 wavelengths
comparison of periods Co = 3rd, Rh = 4th, Ir = 5. Ir > Rh > Co in size

I agree with Caroline Miller, except there is a calculation error above:

E = 3x10^8m/s x 6.626x10^-34J-s / 244x10^-9m = 8.147x10^-16J

The result of that calculation should be 8.147x10^-19J.