Additional Information needed: 1 eV = 1.6•10-19 j

1.) What is the wavelength of a photon absorbed by an electron that gained
1.89 electron-volts, or ev, upon perfect absorption of the photon?

9.) An electron initially in the orbital n = 2 that gained 1.89 eV can be found in
what orbital after gaining that much energy?

10.)
How many moles of photons contain 5,000 J of energy if every photon
has a wavelength of 400 nm?